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Full text of "Anthophyllite asbestos in North Carolina"

CI 

3:77 

C 2 



North Carolina 

Department of Conservation and Development 

Robert L. Stallings, Jr., Director 

Division of Mineral Resources 

Jasper L. Stuckey, State Geologist 

Bulletin 77 

Anthophyllite Asbestos 

in North Carolina 

by 

Stephen G. Conrad, William F. Wilson, Eldon P. Allen 
Division of Mineral Resources 

and 

Thomas J. Wright 

North Carolina State Minerals Research Laboratory 



Raleigh 
1963 



North Carolina 

Department of Conservation and Development 

Robert L. Stallings, Jr., Director 

Division of Mineral Resources 
Jasper L. Stuckey, State Geologist 

Bulletin 77 

Anthophyllite Asbestos 

in North Carolina 

by 

Stephen G. Conrad, William F. Wilson, Eldon P. Allen 
Division of Mineral Resources 

and 

Thomas J. Wright 

North Carolina State Minerals Research Laboratory 



Raleigh 
1963 



MEMBERS OF THE BOARD 
OF CONSERVATION AND DEVELOPMENT 

Hargrove Bowles, Jr., Chairman Greensboro 

Dr. Mott P. Blair, Vice Chairman Siler City 

John M. Akers Gastonia 

Robert E. Bryan , Goldsboro 

Mrs. B. F. Bullard Raleigh 

Daniel D. Cameron Wilmington 

Mrs. Fred Y. Campbell Waynesville 

Dr. John Dees Burgaw 

William P. Elliott, Sr. Marion 

E. Hervey Evans, Jr. Laurinburg 

E. R. Evans Ahoskie 

Andrew Gennett Asheville 

Luther W. Gurkin, Jr. Plymouth 

Woody R. Hampton Sylva 

Charles E. Hayworth High Point 

Gordon C. Hunter Roxboro 

Roger P. Kavanagh, Jr. __ Greensboro 

R. Walker Martin Raleigh 

Carl G. McCraw Charlotte 

Lorimer W. Midgett Elizabeth City 

Ernest E. Parker, Jr. Southport 

R. A. Pool Clinton 

Eric W. Rodgers Scotland Neck 

Robert W. Scott Haw River 

James A. Singleton, Jr. __ Red Springs 

J. Bernard Stein Fayetteville 

Paul H. Thompson Fayetteville 

Charles B. Wade, Jr. Winston-Salem 



ll 






LETTER OF TRANSMITTAL 






Raleigh, North Carolina 
September 25, 1963 



To His Excellency, HONORABLE TERRY SAN FORD 
Governor of North Carolina 



Sir: 

I have the honor to submit herewith manuscript for publication as 
Bulletin 77, "Anthophyllite Asbestos in North Carolina", by Stephen G. 
Conrad, William F. Wilson, Eldon P. Allen and Thomas J. Wright. 

This report contains the results of a detailed investigation of geology 
and mineral dressing characteristics of the anthophyllite asbestos de- 
posits in North Carolina and should be of value to those interested in 
the economic development of these deposits. 

Respectfully submitted, 

Robert L. Stallings, Jr. 
Director 



CONTENTS 



Page 

Abstract 1 

Introduction 1 

Location and distribution 1 

Purpose of investigation . . 1 

Previous work 3 

Present investigation 3 

Acknowledgments 4 

Geography 4 

Climate 4 

Topography 4 

Accessibility 5 

Regional geology 5 

Rock types 5 

Structure and metamorphism 6 

Peridotites and related ultramafic rocks 7 

Distribution 7 

Character and relations 7 

Petrography 8 

Dunite 8 

Saxonite (harzburgite) 8 

Pyroxenite 9 

Enstatolite 9 

Websterite 9 

Soapstone 10 

Alteration of peridotite 10 

Serpentinization 10 

Steatitization 11 

Amphibolization 12 

Chloritization 12 

Origin 12 

Age 13 

Asbestos deposits 14 

Mineralogy and geologic occurrence 14 

Crysotile 14 

Amphibole asbestos 14 

Tremolite 14 

Actinolite 15 

Crocidolite 15 

Amosite 15 

Anthophyllite 15 

Uses 15 

Character and classification of North Carolina deposits 17 

General statement 17 

Cross-fiber veins 17 

Slip-fiber veins 17 

Mass-fiber deposits 17 

Peripheral zones 18 

Anthophyllite-enstatite bodies 18 

Origin of anthophyllite asbestos 19 

History of mining and production 20 

Mining methods 21 

Reserves 21 

Description of mines and prospects 21 

Spruce Pine area 21 

Avery County 21 

Burleson mine 21 

Frank mine 22 

Other prospects 22 



Page 

Mitchell County 22 

J. H. Pannell prospect 22 

Soapstone Branch prospect 22 

Other prospects 24 

Yancey County 24 

Blue Rock mine 24 

Newdale mine ' 25 

J. C. Woody mine 26 

Sam Grindstaff mine 26 

Gas Thomas prospect 27 

C. W. Allen prospect 27 

Other prospects 27 

Lake Toxaway area 27 

Transylvania County 29 

Kilpatrick mine 29 

Oakland mine 29 

Walnut Cove Creek mine 30 

Miller mine 30 

Jennings No. 1 mine 31 

Socrates prospect 32 

Other prospects 32 

Jackson County 32 

Asbestos mine 32 

Rattlesnake prospect 34 

Brockton mine 35 

Bad Creek prospect 35 

Jennings No. 2 mine 36 

Round Mountain mine 36 

Coldsides Mountain mine 36 

Harris prospect 37 

Glenville-Norton area 37 

Bryson-Manus mines 37 

Henderson mine 40 

Alders mine 40 

Holden mine 40 

Other mines and prospects 40 

Macon County 40 

Higdon mine 40 

Peterman mine 42 

Commissioner Creek prospect 42 

Caldwell County 42 

Johns River mine 42 

Evaluation and Beneficiation 45 

Introduction 45 

Dry processing 45 

Sample 1855A 45 

Sample 1855B 45 

Sample 1856 45 

Sample 1857A 45 

Sample 1857B 45 

Sample 1858 49 

Sample 1859 49 

Sample 1872A 49 

Sample 1872B 49 

Comparison of the plus 28 mesh fiber products 49 

Acid leaching and wet processing 50 

Conclusions 50 

References cited 60 












ILLUSTRATIONS 



Page 

Figure 1. Geographic distribution of ultramafic bodies in 

western North Carolina 2 

2. Properties of asbestos fibers 16 

3. Map showing location of asbestos mines in 

Yancey County, North Carolina 23 

4. Map showing location of asbestos mines in the 

Brush Creek area, Yancey County, North Carolina 28 

5. Map showing location of asbestos mines in the 

Sapphire Valley area, North Carolina 33 

6. Map showing location of asbestos mines in Chattooga 

Ridge area, Jackson County, North Carolina 38 

7. Map showing location of asbestos mines in the 
Glenville-Norton area 39 

8. Map showing location of peridotites in Ellijay 

Creek area, Macon County 41 

9. Map showing location of Johns River asbestos prospect, 
Caldwell County, North Carolina 43 

10. Flowsheet for treatment of asbestos ore 46 

11. Flowsheet for low grade, short-fiber ore 50 

Table 1. Distribution and composition of products from 

dry process 47 

2. Distribution and composition of products from 

dry process 47 

3. Distribution and composition of products from 

dry process 48 

4. Properties of plus 28 mesh aspirated fiber 48 

5. Cleaning re-treatment of aspirated fiber 1857A 

Screen analysis of + 28 mesh fiber 1858 49 

6. Comparison of chemical and mineralogical content 

of talc and anthophyllite concentrates 49 

Plate 1. Photomicrographs of typical anthophyllite asbestos 

ores and related rocks 53 

2. Photomicrographs of typical anthophyllite asbestos 

ores and related rocks 55 

3. Photomicrographs of typical anthophyllite asbestos 

ores and related rocks 57 

4. Geology of the Newdale asbestos mine, Yancey County, 

North Carolina in pocket 

5. Geologic cross-sections of the Newdale asbestos mine, 

Yancey County, North Carolina in pocket 

6. Geology of the Blue Rock asbestos mine, Yancey 

County, North Carolina in pocket 

7. Photographs of typical ore samples; and contact 
relationships at the Newdale and Blue Rock mines, 

Yancey County, North Carolina 59 



Vll 



Anthophyllite Asbestos in North Carolina 

by 

Stephen G. Conrad, William F. Wilson and Eldon P. Allen 

ABSTRACT 

Asbestos deposits in North Carolina are associated with a group of basic magnesian rocks com- 
monly referred to as peridotites. These rocks range from dunite to soapstone in composition, and are 
part of a discontinuous belt of ultramafic igneous rocks that traverse the eastern part of North America 
from east-central Alabama to western Newfoundland. In North Carolina the peridotite belt lies chiefly 
west of the Blue Ridge in the mountainous section of the State. However, a few isolated bodies occur in 
the Piedmont section of Burke, Caldwell, Polk, Wilkes and Wake counties. 

Although various types and quantities of asbestiform minerals can be found in practically all of 
the individual peridotite bodies throughout the area, the most important commercial deposits occur as 
anthophyllite asbestos associated with altered bodies in the Toxaway area of Jackson and Transylvania 
counties and in the Spruce Pine area of Yancey and Avery counties. 

Based on the arrangement of the fibers in respect to the wall rock and to each other, three types of 
anthophyllite asbestos ore are recognized. These types are referred to as cross-fiber veins, slip-fiber 
veins and mass-fiber deposits. Cross-and slip-fiber veins are the most common and are present to some 
extent in ultramafic bodies that range in composition from relatively unaltered dunite to soapstone. The 
mass-fiber deposits are divided into peripheral zones associated with partly to thoroughly altered bodies, 
and small, oval shaped bodies composed mostly of anthophyllite and enstatite. 

Past production from North Carolina has been mostly from mass-fiber deposits of the peripheral 
zone type. However, mass-fiber deposits of the anthophyllite-enstatite variety appear to have consider- 
able potential. 

The North Carolina State Minerals Research Laboratory determined the physical and chemical 
properties of nine selected ores and investigated methods of separating the major mineral components 
by dry and wet benefication processes. 



INTRODUCTION 



Location and Distribution 

The asbestos deposits in North Carolina are 
associated with a group of basic magnesian rocks, 
commonly referred to as peridotites. These per- 
idotites are part of a discontinuous belt that tra- 
verses the eastern part of North America from 
east-central Alabama to western Newfoundland, 
a distance of more than 2,000 miles. In North 
Carolina the peridotite belt lies chiefly west of the 
Blue Ridge in the mountainous section of the 
state ; however, a few isolated bodies occur in the 
Piedmont section in Burke, Caldwell, Wilkes and 
Wake counties. 

Although various types and quantities of asbes- 
tos can be found in most of the individual per- 
idotite bodies throughout the area, practically all 
of the commercial deposits of asbestos occur in 



highly altered bodies in the Lake Toxaway area of 
Jackson and Transylvania counties and in the 
Spruce Pine area of Yancey and Avery counties. 

The accompanying map (Figure 1) of a portion 
of western North Carolina shows the distribution 
of the main belt of peridotites and related ultra- 
mafic rocks. Owing to the fact that most of the 
peridotites are lenticular or oval masses, usually 
less than 300 or 400 feet in length, it was neces- 
sary to exaggerate their dimensions on the map in 
order for them to be distinct. 

Purpose of Investigation 

North Carolina has been a small, but consistent 
producer of anthophyllite asbestos for many years. 
Although the peridotite bodies with which the 
asbestos is associated have been studied at various 




~ a 
to 

VI 

li 
2E 

<3g 



times for other economic minerals, such as olivine, 
vermiculite, chromite, and corundum, there have 
been no systematic studies of asbestos. 

Asbestos is a highly important industrial min- 
eral for which there are practically no substitutes. 
In view of the fact that the demand for asbestos 
should continue to increase for some years to come 
and that research is developing new uses for all 
varieties of asbestos, an appraisal of North Caro- 
lina's anthophyllite asbestos resources seems de- 
sirable at this time. 

It is the purpose of this report to present as 
complete an appraisal as possible of the antho- 
phyllite asbestos resources of the State. A com- 
bination of several factors indicate that the pros- 
pects appear very favorable for developing an im- 
portant asbestos producing industry in the State 
within the next few years. It is hoped that this 
report will contribute materially to the develop- 
ment of such an industry. 

Previous Work 

Owing to the fact that an unusual number of 
economic minerals are associated with them, the 
peridotites have been of interest for well over 
100 years. Because of its value as a natural abra- 
sive, next to diamond in hardness, and as a gem 
stone, corundum was the first mineral of the peri- 
dotites to draw attention. The first reference to 
corundum in North Carolina appeared in an ar- 
ticle in the American Journal of Science by John 
Dickson in 1821. Kerr (1875, pp. 129-130, 293, 
298-299) briefly describes the "chrysolyte (dun- 
yte) " ledges and the associated minerals serpen- 
tine, asbestos, chromite and corundum. Included 
in this same volume (Appendix D, pp. 91-97) is a 
more detailed discussion of corundum and its 
associated rocks by C. D. Smith. 

The first systematic study of the peridotites in 
western North Carolina was by Lewis (1896). 
This was a preliminary report on corundum and 
the basic magnesian rocks based on field studies 
during 1893 and 1894. This study was expanded 
and continued for several more years and in 1905 
Pratt and Lewis published a comprehensive re- 
port on the geology, petrology and mineralogy of 
the belt of corundum-bearing rocks in western 
North Carolina. This report is considered to be 
somewhat of a classic in geologic literature and 
has served as the bases of much subsequent work. 
It was a valuable aid in the present study and 
greatly facilitated the fieldwork. 



After the introduction of artificial abrasives 
about 1900, the importance of corundum was 
greatly reduced and corundum mining in North 
Carolina ceased about 1906. Subsequently, the 
peridotites received very little attention until the 
Tennessee Valley Authority began its study of 
regional products during the middle and late 
1930's. Several reports dealing with economic 
minerals associated with the peridotites resulted 
from studies conducted by the Tennessee Valley 
Authority in cooperation with the North Carolina 
Division of Mineral Resources. The first of these 
was by Hunter (1941) on the fosterite olivine de- 
posits. Others were by Hunter, Murdock and Mac- 
Carthy (1942) on the chromite deposits and by 
Murdock and Hunter (1946) on the vermiculite 
deposits. During World War II the U.S. Geologi- 
cal Survey and the U.S. Bureau of Mines investi- 
gated several of the abandoned corundum mines 
in Clay, Macon and Jackson counties as a possible 
domestic source of corundum. The results of these 
studies were reported by Ballard (1947a, 1947b) 
and Hadley (1949). 

It should be pointed out that the above men- 
tioned publications represent only the most sig- 
nificant work done on the peridotites of North 
Carolina. As the peridotite belt traverses prac- 
tically the entire length of eastern North America, 
there is a vast amount of literature available that 
has been prepared by other state surveys, the 
federal survey, the Canadian survey and individ- 
ual workers. However, as this report is concerned 
only with the asbestos deposits in North Carolina, 
it is beyond its scope to review all of the literature 
on asbestos and the peridotites. 

Present Investigation 

The present geologic study of anthophyllite as- 
bestos deposits was begun in the spring of 1960. 
The purpose of the study was to gather as much 
information as possible on the distribution, char- 
acter, origin and potential reserves of asbestos in 
North Carolina. 

As the individual peridotite bodies number in 
the hundreds, it was possible to visit only a limited 
number of deposits in the time alloted to the 
project. However, an attempt was made to locate 
and examine all of the deposits that had been 
worked for asbestos plus as many of the other 
peridotites as possible. Particular attention was 
given to the deposits currently being mined and 
to those that were mined in recent years. Detailed 



geologic maps were made of three selected deposits 
and geologic sketch maps were made of numerous 
others. 

Samples considered to be representative of the 
different types of ore and associated rocks were 
collected from most of the deposits examined. 
Some 50 thin-sections were prepared from these 
samples for petrographic analyses. 

An important phase of this project was the 
mineral dressing studies conducted by the North 
Carolina State College Minerals Research Labora- 
tory. Thomas J. Wright, Mineral Dressing Engi- 
neer, carried out these studies, the results of which 
are discussed in detail in the latter part of this 
report. 

Acknowledgments 

This report was authorized by and conducted 
under the direction of Dr. Jasper L. Stuckey, 
State Geologist, who also furnished much back- 
ground material and spent several days in the 
field with the writers when the project was initi- 
ated. 

Many persons have made important contribu- 
tions to this investigation. Particularly helpful 
were Mr. Fred A. Mett, President, and Mr. Frank 
Burleson, Mine Foreman, of the Powhatan Mining 
Company. Both were very generous with their 
time in locating abandoned asbestos workings, 
and gave freely of their extensive knowledge of 
asbestos gained through many years of explora- 
tion and mining of asbestos in North Carolina, 
Georgia and South Carolina. Mr. Joseph H. Kettle- 
strings, President, and Mr. Joe Sherertz, Mine 
Superintendent, of the Blue Rock Mining Corpora- 
tion of Illinois were also most helpful and coopera- 
tive. Mr. Louis Dendy, Highlands, acted as guide 
on several occasions and his familiarity with the 
peridotites in Macon, Jackson and Transylvania 
counties save the writers much time and effort in 
locating many of the peridotites in those counties. 
Local residents and land owners of the various 
areas visited were most helpful in supplying back- 
ground material and directions and their coopera- 
tion is gratefully acknowledged. 

Mr. William T. McDaniel, Chief Engineer, 
North Carolina State College Minerals Research 
Laboratory, made many helpful suggestions as to 
how the work of the Division of Mineral Resources 
and that of the Minerals Research Laboratory 
could best be coordinated. He also spent several 
days in the field with the writers collecting bulk 



samples for laboratory analyses. His cooperation 
and advice and that of the other personnel at the 
Minerals Research Laboratory has added much 
to this report. 

GEOGRAPHY 

Climate 

The main area of the peridotite belt is coinci- 
dent with the mountain section of the State, and 
therefore falls within a distinct climatic zone. The 
high elevations of the mountains have a two-fold 
influence on the climate in this section of the 
State. First, is a general reduction in temperature 
and secondly, is an increase in rainfall. This re- 
duction in temperature results in pleasant sum- 
mer weather, but conversely it also means that the 
mountain section generally experiences the coldest 
temperature in the State during the winter 
months. The mean annual temperature for the 
area is about 54 degrees, but varies between the 
extremes of 45 and 58 degrees. 

Rainfall in the mountain region varies more 
than in any other section of the State. The largest 
amounts occur in the southern part of Transyl- 
vania, Jackson, Macon and Clay counties and 
along the southeastern crest of the Blue Ridge. 
This section of the mountains receives more rain- 
fall than anywhere else east of the Rockies. In a 
small area in the vicinity of Highlands, Macon 
County, annual rainfall is up to 80 inches. The 
driest part of the State is also in the mountain 
section. A small area between Asheville and Mar- 
shall receives slightly less than 40 inches of rain 
annually. 

This significant rainfall variation is attributed 
to the fact that the high rainfall areas in the 
southern and eastern sides of the mountains re- 
ceive their principal rainbearing winds from the 
east and south. The moisture-laden winds coming 
up over the mountains from the east or south, re- 
lease most of the possible rain over the upslope, 
and descend to lower elevations as relatively dry 
winds. 

Topography 

Except for a relatively few isolated ultramafic 
bodies which occur in the Piedmont division, the 
peridotite belt lies entirely within the Mountain 
division of the Appalachian province. This pro- 
vince is made up of many minor ranges and, un- 
der various names, extends in a southwest to 



northeast direction from central Alabama to New 
York. However, western North Carolina is the 
culminating region of the Appalachian Mountains 
and contains the greatest masses, the highest ele- 
vations and the most rugged topography in the 
Mountain division. 

In North Carolina the eastern border of the 
Mountain division is marked by the Blue Ridge 
Mountains, which rise rather abruptly some 1500 
to 2000 feet above the Piedmont. The average ele- 
vations of the Blue Ridge ranges between 3000 
and 4000 feet, but a few points approach 6000 feet 
in elevation. The western boundary is marked by 
the Unaka and Great Smoky Mountains which 
have elevations ranging from 3000 to 6000 feet. 
Between these two bordering chains lies the pla- 
teau region of western North Carolina. 

The plateau region is divided by a number of 
cross ridges into several smaller plateaus or 
basins. These cross ridges run more or less per- 
pendicular to the bordering mountain chains in 
much the same manner as rungs on a ladder. The 
most prominent ridge is the Black Mountains, 
which consist of a single ridge that extends some 
15 miles from where it leaves the Blue Ridge and 
contains a dozen peaks which exceed 6000 feet in 
elevation. One of these, Mount Mitchell, has an 
altitude of 6,684 feet and is the highest mountain 
east of the Mississippi River. Other cross ridges, 
from northeast to southwest, are the Pisgah 
Mountains, New Found Mountains, Balsam Moun- 
tains, Cowee Mountains, Nantahala Mountains 
and the Valley River Mountains. 

The mountain section is about 200 miles long 
and varies from 15 to 50 miles in width. Its total 
area is about 6000 square miles. The crest of the 
Blue Ridge marks the Eastern Continental Divide. 
Streams flowing to the west eventually drain into 
the Gulf of Mexico, while those flowing east drain 
into the Atlantic Ocean. 

Accessibility 

Although the mountain section contains the 
most rugged topography in the State, the area is 
made readily accessible by a network of state and 
federal highways. Major highways that traverse 
the area are U.S. Highways 19, 23, 25, 64, 70, 
221, 321 and 421. In addition, Interstate High- 
ways 26 and 40 will also eventually traverse the 
area. Each county contains numerous State main- 
tained secondary paved and unpaved all-weather 
roads that make even the most remote areas rea- 
sonably accessible. The entire mountain section is 



covered with a maze of old wagon and logging 
roads. Many of these can be traveled without too 
much difficulty by jeep or other 4-wheel drive 
vehicles. 

Asheville is the rail center of the area. The 
Southern Railway System operates lines from 
Asheville southwest through Murphy into Geor- 
gia, northwest through Marshall into Tennessee, 
southeast through Tryon into South Carolina, and 
east through Marion to points east and north. The 
Clinchfield Railroad serves the northeast section 
of the area. Its main line runs from Marion, 
through Spruce Pine and on northwestward into 
Johnson City, Tennessee. 

In addition to highway and rail transportation, 
Asheville is serviced by daily flights of Piedmont, 
United and Delta Airlines. 

REGIONAL GEOLOGY 

Rock Types 

The main belt of ultramafic rocks in North 
Carolina lies in the Blue Ridge province and is 
associated with a vast complex of Precambrian 
metamorphic and plutonic rocks (King, 1955). 
The metamorphic rocks consist mainly on silice- 
ous, micaceous gneisses and schists interlayered 
with hornblende gneisses and schists. Keith (1903, 
1904, 1905, 1907a, 1907b) referred to these rock 
types as Carolina gneiss and Roan gneiss, respec- 
tively. 

The Carolina type rocks vary considerably in 
composition and include muscovite-biotite gneiss, 
biotite gneiss and schist, mica schist, quartz-mica 
schist, quartzite, and garnet-and kyanite-mica 
gneiss and schist. The mica gneisses contain abun- 
dant orthoclase and plagioclase feldspars and var- 
ious proportions of muscovite, quartz, garnet and 
other accessory minerals. With a decrease in the 
feldspars, and an increase in quartz and the micas, 
the gneisses grade into mica schist, some of which 
contain practically no feldspar (Olsen, 1944, p. 
17). Many of the Carolina type gneisses and 
schists apparently were originally sedimentary 
beds ; however, some show relict volcanic struc- 
tures, and others may have been intrusive igneous 
rocks. 

Hornblende, or Roan type rocks, are interlay- 
ered with the micaceous rocks in various propor- 
tions. In some areas, notably the Spruce Pine dis- 
trict of Mitchell, Yancey and Avery counties, 
large areas are underlain almost entirely by horn- 
blende rocks. The two most abundant types of 



hornblende rocks are hornblende schist and horn- 
blende gneiss. The schistose rocks are composed 
almost entirely of needle-like crystals of horn- 
blende and minor amounts of quartz and feldspar. 
The gneissic rocks are composed mostly of horn- 
blende, plagioclase feldspar and quartz. In many 
cases, the hornblende is segregated into thin 
layers that are separated by thicker layers com- 
posed mainly of quartz and feldspar. Many of the 
Roan type gneisses and schists probably origi- 
nated either as intrusive rocks, or volcanic flows 
of intermediate to basic composition. However, 
much of it is thought to have been impure cal- 
careous sedimentary deposits interbedded with 
the originally sandy and shaly beds of the Caro- 
lina type rocks. 

Large areas in the Blue Ridge (see Geologic 
Map of North Carolina, 1958) are underlain by 
rocks mapped by Keith (1903, 1904, 1905, 1907) 
as Cranberry granite and Henderson granite. 
These rocks are highly metamorphosed and con- 
sidered by recent workers (Eckelmann and Kulp, 
1956) to be sedimentary in origin and strati- 
graphically equivalent. The Cranberry is pre- 
dominantly a layered gneiss; however, it varies 
considerably in composition and contains num- 
erous granite layers and layers of mica schist and 
amphibolite. The Henderson is a relatively uni- 
form gneiss containing abundant eye-shaped feld- 
spar crystals, some up to an inch long, that give 
it a distinctive appearance. 

Granitic rocks intrude the metamorphic com- 
plex in several parts of the region. Southwest of 
Asheville, in Transylvania, Jackson and Macon 
counties, occur large areas of Whiteside granite 
(Keith, 1907). It is predominently a light grey to 
white, equigranular, massive granite that con- 
tains numerous inclusions of the surrounding 
gneisses and schists, and many associated pegma- 
tites. Large masses of a coarse-grained pegmatitic 
granite, commonly referred to as alaskite, occur 
in the vicinity of Spruce Pine, Mitchell County. 
Associated with the alaskite are numerous pegma- 
tites which are found near the margins of the 
alaskite bodies and in the surrounding gneisses 
and schists. Other masses of granite rocks occur 
in Swain, Haywood and Madison counties, west of 
the main belt of ultramafic rocks. 

Interrupting the metamorphic and plutonic 
rocks at several places in the Blue Ridge province, 
are areas of relatively low-grade metamorphosed 
sedimentary rocks of Cambrian (?) age. All of 
these areas are complex structural features and 



are referred to as the Murphy belt (Keith, 1907; 
Van Horn, 1950), the Hot Springs window (Oriel, 
1950) , the Grandfather Mountain window (Keith, 
1903; Bryant and Reed, 1960), and the Brevard 
belt (Keith, 1905). 

The metamorphic and plutonic complex is bor- 
dered on the west and northwest by the Ocoee 
series, which is an extremely thick sequence of 
clastic sedimentary rocks of Late Precambrian 
age (King et. al., 1958). These rocks underlie a 
large area in westernmost North Carolina and 
form the Great Smoky Mountains. However, they 
are west of and devoid of any ultramafic igneous 
rocks. 

Structure and Metamorphism 

Except for a relatively few mafic intrusive 
rocks of Triassic age, the rocks of the Blue Ridge 
province have been subjected to several successive 
episodes of deformation and metamorphism. The 
resulting structural and metamorphic features 
are thus complex and only generally understood 
in many areas of the region. 

All of the metamorphic rocks of the region are 
generally strongly folded, and have a well devel- 
oped foliation that is usually parallel to the com- 
positional layering in the gneisses and schists. 
This foliation, or cleavage, in most cases com- 
pletely obscures the primary structures and has 
a regional northeast strike and dips to the south- 
east at moderate to steep angles. 

The degree of regional metamorphism varies 
considerably within the area. Metamorphic grade 
ranges from relatively low-grade gneisses and 
schist to middle-and high-grade staurolite and 
kyanite schist. Detail geologic studies in the 
Spruce Pine district (Brobst, 1962) and Grand- 
father Mountain area (Bryant and Reed, 1962) 
and radiometric age determinations (Long, Kulp 
and Ecklemann, 1959 ; Tilton and others, 1959 ; 
Kulp and Eckelmann, 1961) reveal the rocks in 
these areas have been subjected to two, and pos- 
sible four, periods of metamorphism. 

Clearly recorded metamorphic episodes have 
been established for the Precambrian (1000 to 
1100 million years ago) and the middle Paleozoic 
(350 million years ago) . A possible early Paleozoic 
regional metamorphism (450 million years ago) 
and an episode of low grade regional metamor- 
phism during late Paleozoic time have been sug- 
gested on the basis of a few radiometric dates and 
other geologic evidence; however, these periods 
are as yet only tentative (Bryant, 1962, p. 20-23). 



6 



PERIDOTITES AND 
RELATED ULTRAMAFIC ROCKS 

The peridotites in North Carolina were de- 
scribed in great detail by Pratt and Lewis (1905) . 
However, that publication has been out of print 
and unavailable for general use for a number of 
years. It is beyond the scope of this report to 
discuss the geology of the peridotites in great 
detail. However, the asbestos deposits are directly 
related to the peridotites, and it is necessary to 
have some knowledge of the peridotites before 
the asbestos deposits can be understood. There- 
fore, a general discussion of the periodotites is 
included for the benefit of those readers not 
familiar with the geology of these rocks. 

Distribution 

As previously stated, the peridotites and re- 
lated ultramafic rocks in North Carolina are part 
of a discontinuous belt that traverses the eastern 
part of North America for a distance of more 
than 2000 miles. In North Carolina the main belt 
of peridotites lies west of the Blue Ridge and east 
of the Great Smoky and Unaka Mountains. A 
number of isolated bodies occur east of the Blue 
Ridge in several of the Piedmont counties. 

The peridotite belt enters North Carolina from 
Georgia in the southwestern counties of Clay, 
Macon and Jackson. It is at its greatest width 
in this area and extends from Shooting Creek on 
the west to Brevard on the east. It continues in a 
northeast direction through parts of Transylvania, 
Haywood, Buncombe, Madison, Yancey, Mitchell, 
Avery, Watauga, Ashe and Alleghany counties. 
In the southwestern counties the peridotite bodies 
are scattered over an area nearly 40 miles wide. 
However, from north of Waynesville to the vicin- 
ity of Burnsville the peridotites are confined to 
a single narrow belt. In Yancey County the bodies 
again become more widely distributed and the 
belt is wider than elsewhere north of the French 
Broad River. In Alleghany County, the peridotites 
pass into Virginia, where they continue north- 
eastward for some distance. 

Character and relations 

Although the peridotites are quite extensive in 
western North Carolina the actual area they cover 
is comparatively small. With a few exceptions, 
the average area of outcrop covers only a few 
acres and in many cases less than an acre. The 
peridotite body at Buck Creek, Clay County, is 
one of the largest single bodies in the Appalachian 



region. It covers a little more than 300 acres, or 
about one-half a square mile (Hadley, 1949, p. 
109). 

The Webster-Balsam area in Jackson County 
contains the largest peridotite mass in the State. 
A number of disconnected outcrops form an elipti- 
cal shaped body that is commonly referred to as 
the Webster ring-dike. It has a major axis which 
is about six miles long and is alined northeast- 
southwest, and a minor axis about three and one- 
half miles long alined northwest-southeast. The 
largest single body exposed in the ring-dike is the 
Webster peridotite, which is a crescent shaped 
body 2.75 miles in length and up to 1800 feet in 
width. It is exposed from a short distance north 
of the town of Webster, southward to a point 0.75 
mile south of the Tuckaseigee River, and then 
nearly due east for 1 mile. 

Other large peridotite bodies in the Webster 
ring-dike are the Balsam Gap deposit, the Dark 
Ridge deposit, the Addie deposit and the Cane 
Creek deposit. Most of the commercial olivine pro- 
duction in North Carolina has come from several 
of the peridotite bodies in the Webster ring-dike. 

Most of the peridotites are lens shaped bodies 
in which the major axis is two to three times as 
long as the minor axis. The major axis is usually 
alined more or less parallel to the regional schis- 
tosity, but crosscutting bodies are not uncommon. 
In a few instances, such as the Webster peridotite, 
part of the body is alined parallel to the schis- 
tosity and part of it cuts across the schistosity. 
Although most of the peridotites are lens shaped 
or elliptical in outline, some masses are nearly 
uniform in width on outcrop and can be traced 
along strike for relatively long distances. Others 
are more radical in outline, having finger-like, or 
curved and irregular apophyses which branch off 
of the main mass and cut into the country rock. 

On outcrop, the peridotites exhibit unique char- 
acteristics and are easily distinguished from the 
surrounding gneisses and schists. They are mas- 
sive and more resistant to weathering than rocks 
with a well developed schistosity. Consequently, 
the larger peridotite bodies often form prominent 
knobs and peaks when they occur on or near the 
crests of hills or mountains, and moderate cliffs 
or spurs when on the slopes. The contact between 
the peridotite and adjacent rock is always sharp 
and characterized by a zone of schistose talc, 
vermiculite and chlorite. This zone ranges from 
a few inches to several feet wide, is always present 
and is clearly of secondary origin. 



Those peridotites composed mostly of olivine 
(dunite) always form a barren, rocky surface 
that is covered with a thin, poor soil that is con- 
spicuously lacking in vegetation. This lack of 
vegetation is in sharp contrast to the surrounding 
thick growth of vegetation which usually grows 
in the soil derived from the gneisses and schists. 
The peridotite protrudes above the surface as 
rounded, solution-pitted, boulder-like outcrops 
and ledges. The outcrops have a characteristic 
dull-brown or rusty color, which is the result of 
the weathering of olivine. 

Petrography 

Peridotite is a general term used for essentially 
nonfeldspathic plutonic rocks consisting mainly of 
olivine, but which may contain varying amounts 
of other mafic minerals such as amphiboles, 
pyroxenes, and in some cases mica. The peridotites 
in North Carolina vary considerably in minera- 
logical composition, both within individual de- 
posits and from one deposit to another. By detail 
petrographic analysis it is possible to identify 
numerous individual rock types that occur in the 
peridotites. However, many of these types are 
compositional variations that are not perceptible 
in hand specimens or on outcrop. For all practical 
field purposes, the ultramafic rocks can generally 
be classed as dunite, saxonite, pyroxinite or soap- 
stone. The following is a brief description of these 
major rock types : 

Dunite: Dunite is the most important variety 
of peridotite in North Carolina. It is composed 
almost entirely of olivine, but contains a small 
percentage of a few primary accessory minerals 
such as chromite and enstatite. 

Olivine is a magnesium iron orthosilicate, 
(Mg,Fe) 2 Si0 4 . However, the ratio of Mg:Fe 
varies considerably. Thus the composition of 
olivine can range from forsterite (Mg 2 Si0 4 ) at 
one end of the series to fayalite (Fe 2 Si0 4 ) at the 
other. Previous work by Hunter (1941, p. 13) in- 
dicates that the average composition of the un- 
altered olivine deposits in North Carolina is about 
90 percent forsterite and 10 percent fayalite. 

The largest bodies of peridotite are dunite 
masses, some of which are composed of 90 per- 
cent, or more, olivine and slightly serpentinized 
olivine. Some of these dunite bodies, such as the 
Buck Creek deposit, and those in the Webster 
ring-dike, crop out over relatively large areas, 
extend to unknown depths and contain unlimited 
amounts of minable olivine. 



In most of the dunite bodies the fresh olivine 
is pale green, yellowish-green or gray-green in 
color. It is predominantly fine to medium grained 
and granular. The individual grains rarely occur 
in distinct crystal form, but are usually irregular 
in outline and fit together perfectly without in- 
terstitial spaces or cementing material. This lack 
of cementing material and the granular texture 
combine to produce a friable, sandy rock upon 
weathering. 

The dunites contain a wide variety of primary 
and secondary accessory minerals. Chromite is 
the most common primary mineral and is char- 
acteristic of all the peridotites throughout the 
region. It occurs as small to medium, well-devel- 
oped octahedral crystals that are disseminated 
throughout the dunite, or as small lenses and thin 
veins of massive chromite surrounded by olivine. 
In most cases the chromite constitutes less than 
one precent of the bulk of the rock, but in some 
places it makes up as much as 25 percent of the 
dunite (Hunter, 1941, p. 28). Sporadic attempts 
have been made to mine chromite at several of 
the dunite bodies in North Carolina, but none of 
these attempts have resulted in successful mines. 
In addition to chromite, other primary accessory 
minerals often associated with the dunites include 
enstatite and picotite. 

Olivine is quite susceptible to alteration and 
weathering, and these processes have produced a 
number of secondary minerals which are com- 
monly associated with the dunites and all of the 
peridotites in general. Serpentine, talc, vermicu- 
lite, chlorite and anthophyllite are present, with- 
out exception, in varying amounts in the dunites. 
Other minerals often found associated with the 
dunites include magnetite, actinolite, phlogopite, 
garnierite, magnesite, corundum, spinel, picro- 
lite, limonite, chalcedony, sepiolite (?), and oc- 
casionally tourmaline. 

Saxonite (harzburgite) : Saxonite, like dunite, 
is composed mostly of olivine and the usual acces- 
sory minerals, but in addition contains significant 
amounts of the orthorhombic pyroxenes, enstatite 
and bronzite. The enstatite and bronzite occur as 
well developed, lath shaped crystals that are dis- 
seminated through the olivine. Usually, the pyro- 
xene crystals are much larger than the olivine 
grains. Crystals up to one-half inch long are com- 
mon, and crystals an inch or more in length are 
frequently present. In many cases, the enstatite 
and bronzite have been partly to completely al- 
tered to talc. 



8 



Occasionally an individual peridotite body is 
composed principally of saxonite. More often, how- 
ever, saxonite forms part of a larger dunite body, 
being in contact with or completely surrounded 
by the dunite. 

Pyroxenite: As the name implies, rocks of this 
type are composed essentially of pyroxene. Two 
types of pyroxenite are found in closest connec- 
tion with the peridotites of the area, enstatolite 
and websterite. 

Enstatolite : This rock is composed mostly, and 
in some cases almost exclusively, of the orthor- 
hombic pyroxene, enstatite. Although it is not 
nearly as common as the peridotites, enstatolite 
is found throughout the region. In some places it 
forms a minor part of a larger peridotite mass 
as at Corundum Hill, Macon County, and at the 
Sapphire mine in Jackson County. More often, as 
at other localities in the Toxaway area and in 
Yancey and Avery counties, it forms separate 
rock masses of varying size. 

The enstatite usually occurs as large, bladed. 
interlocking crystals of gray to bluish-gray color 
that are oriented in all directions in respect 
to each other. Individual crystals as much as six 
inches long and one and a half inches wide are not 
uncommon. In most cases, the enstatite has under- 
gone variable degrees of alteration, but the origi- 
nal character of the mineral is still easily dis- 
cernible. The alteration products consist almost 
entirely of fibrous anthophyllite and talc along with 
minor amounts of chlorite. The talc occurs around 
the edges and along the cleavage cracks of the 
enstatite crystals and also as disseminated and 
variously oriented flakes and foliae. Chlorite is 
often closely associated with the talc. The antho- 
phyllite usually takes the form of the original 
enstatite crystal with the fibers oriented parallel 
to the long direction of the enstatite. It is also 
present as lath shaped crystals that penetrate the 
enstatite in all directions. In some deposits, the 
replacement of enstatite by fibrous anthophyllite 
and talc is practically 100 percent complete; 
whereas, in others unaltered enstatite is present 
in amounts in excess of 50 percent. 

The enstatite crystals enclose irregular masses 
and individual grains of olivine and numerous 
grains of magnetite and chromite. Olivine is us- 
ually present in amounts of less than 10 percent. 
Minor amounts of magnesite are present as ir- 
regular masses enclosed in, or around the edges, 
of the enstatite. 



Without exception, the enstatolite bodies are 
considerably smaller than even the moderate size 
dunite bodies. The largest enstatolite bodies do 
not exceed 300 or 400 feet in their longest dimen- 
sion, and most of them are more on the order of 
100 to 200 feet in length. Quite frequently several 
small, but separate enstatolite bodies will occur in 
close proximity to each other. 

Observations made at abandoned corundum 
workings and from more recent asbestos mining 
operations, clearly demonstrate that the enstato- 
lite bodies are isolated, pod-like and eliptical 
shaped masses that do not extend to any great 
depths. In general, the long dimension of the 
enstatolite bodies conform to the regional schis- 
tosity of the country rocks. However, in a few 
instances it appears that the major axis is in- 
clined at a steep angle to the horizontal and the 
body is actually oriented in a vertical or near 
vertical position. 

The enstatolite bodies are completely enclosed 
in an envelope of schistose talc, chlorite and ver- 
miculite that ranges from a few inches to over two 
feet in thickness. In some places, the enclosing 
envelope is composed entirely of unusually large, 
foliated crystals of emerald green chlorite. The 
contact between the chlorite and adjacent enstato- 
lite is quite sharp. The contact between the enclos- 
ing envelope and adjacent country rock is also 
sharp and is frequently marked by slickensides. 

The areas in which individual enstatolite bodies 
are most common are coincident with areas of acid 
igneous intrusive rocks. Namely, the Toxaway 
area of Jackson and Transylvania counties, in 
which occur large masses of the Whiteside granite 
and associated pegmatites, and the Spruce Pine 
pegmatite district of Mitchell, Yancey and Avery 
counties. Although no pegmatites have been ob- 
served that directly cut an enstatolite body, num- 
erous examples can be cited in which pegmatites 
are in contact with, or very closely associated 
with enstatolite. In fact, this relationship was 
observed at all the enstatolite bodies examined 
during this investigation. It is particularly promi- 
nent at those deposits where mining operations 
have exposed the contact zone between the enstato- 
lite and surrounding country rock. 

Websterite : This rock type is very restricted in 
its occurrence and is, therefore, somewhat unique. 
It was first described and named by Williams 
(1891) from specimens collected a short distance 
southeast from the town of Webster, Jackson 



9 



County. Here, the websterite forms a distinct 
elongated mass that is completely surrounded by 
dunite. It has a maximum outcrop width of about 
500 feet and can be traced northwestward along 
the strike of the dunite for about one mile (Pratt 
and Lewis, 1905, p. 95) . It is also found associated 
with dunite about 3 miles east of Webster on Cane 
Creek, one mile north of its confluence with the 
Tuckaseigee River. Soil derived from websterite 
supports a moderate growth of vegetation which 
is in sharp contrast to the relatively barren dunite 
and the websterite is therefore easily distin- 
guished in the field. 

Websterite is composed of the monoclinic pyro- 
xene diopside and the bronzite variety of the or- 
thorhombic pyroxene enstatite. The minerals are 
present as an equigranular aggregate in which 
the diopside usually prevails over the enstatite. 
Large anhedral crystals of both pyroxenes are 
disseminated throughout the mass of the rock. It 
closely resembles the dunite with which it is as- 
sociated, but it has a brighter green color than 
the dunite and is much less altered. 

Soapstone: Soapstone is a general term applied 
to massive, impure talc-rich rocks derived from 
peridotites and pyroxenites. It is a combination 
of several minerals and its composition is there- 
fore quite variable. The chief constitutents usually 
include talc, amphibole and chlorite. In some cases, 
soapstone forms a minor part of a larger peridotite 
body, or it may occur as a separate mass. It is 
common throughout the length of the peridotite 
belt in North Carolina, but appears to be more 
plentiful toward the northeast end of the belt. In 
Ashe and Alleghany counties, a number of rela- 
tively large ultramafic bodies appear to be com- 
posed entirely of soapstone. 

Alteration of Peridotite 

In their present state, the peridotites and re- 
lated ultramafic rocks represents a variety of dis- 
tinct but related rock types. However, it is gen- 
erally believed that all of the peridotites, when 
first formed, were either dunite or saxonite of a 
very similar and uniform mineralogical and 
chemical composition. Since their formation, these 
rocks have been involved in one or more episodes 
of regional metamorphism and subjected to hydro- 
thermal solutions emanating from granite and 
pegmatite intrusions. These processes have differ- 
entially altered the original character of the ultra- 
mafic rocks and have produced the variety of rock 
types now present. 



Four processes of alteration and the resulting 
products are clearly discernible in the North Caro- 
lina peridotites. These processes are (1) serpen- 
tinization, (2) steatitization, (3) amphibolization 
and (4) chloritization. 

All of these processes occur more or less to- 
gether throughout the length of the peridotite 
belt. However, one mode of alteration usually 
predominates over the others and thus some sec- 
tions of the belt are characterized by the abun- 
dance of certain alteration products such as ser- 
pentine, talc, amphibole, etc. The processes of 
serpentinization and steatitization are the most 
widespread and are in fact present to some degree 
in all of the peridotites. Amphibolization and 
chloritization are more local in their development. 

These modes of alteration of the peridotites, 
particularly serpentinization and steatitization, 
have been the subject of considerable research 
and much controversy for many years. It was be- 
yond the purpose of this study to make a separate 
investigation of the alteration processes as they 
apply to the North Carolina peridotites. There- 
fore, only a brief discussion of the processes, as 
described in previous literature, and their pos- 
sible application to the North Carolina peridotites 
is included here. 

Serpentinization: Serpentinization is defined as 
that process of alteration in which f erromagnesian 
minerals, or rocks, are converted to serpentine 
minerals. This process is best exemplified in the 
dunites and saxonites where the olivine has been 
partly to completely altered to serpentine. 

In the dunites and saxonites the formation of 
serpentine always begins along the periphery of 
the olivine grains and progresses toward the cen- 
ter. Under the microscope, all stages of develop- 
ment can be observed. In some cases the serpen- 
tinization has been so complete that only a small 
remnant or skeleton of the original olivine crystal 
remains. 

Although all of the dunites exhibit some ser- 
pentinization the degree of alteration varies from 
one deposit to another. Many of the larger dunite 
masses contain a core of relatively unaltered, 
granular olivine which is more or less concentri- 
cally surrounded by more throughly serpentinized 
olivine. This type of zoning is common among the 
dunites throughout the peridotite belt. 

The process by which serpentinization of ultra- 
mafic igneous rocks takes place has long been a 
controversial subject. However, recent theories 
generally subscribe to one or more of the follow- 



10 



ing modes of origin: (1) autometamorphism- 
alteration of peridotite and dunite by a late 
stage portion of the ultramafic magma while it is 
in the process of crystallization; (2) direct pre- 
cipitation of serpentine from a hydrous peridotite 
magma; (3) alteration of dunite and peridotite 
by hydrothermal solutions, generally presumed to 
come from granites younger than the peridotites ; 
and (4) serpentinization during tectonic trans- 
port, with water supplied from the enclosing 
rocks. At one time, serpentinization of dunite and 
peridotite was considered to be a surface phe- 
nomenon due to weathering processes. However, 
it is now well established that serpentinization is 
a deep-seated reaction and that weathering proc- 
esses are responsible for the formation of only 
negligible amounts of serpentine. 

Recent experimental work on the system 
MgO-SiO, -H 2 by Bowen and Tuttle (1949) has 
added greatly to the understanding of the ultra- 
mafic complexes and the process of serpentiniza- 
tion. Their work has, to a certain extent, elimi- 
nated some of the former conflicting theories of 
serpentinization. Based on their experimental 
data, Bowen and Tuttle (1949, p. 453) conclude 
that, ". . . our results seem to exclude the possi- 
bility of the intrusion at comparatively low tem- 
peratures of a magma of serpentine composition 
which crystallizes, wholly or in part, directly to 
serpentine. Many geologists believe that the field 
data indicate such an origin for serpentine. The 
more modern and systematically developed form 
of the hypothesis (Hess, 1938) postulate that 
there is early separation of olivine and pyroxene, 
but that they are transformed by their own highly 
aqueous mother liquor, an autoserpentinization. 
Other geologists believe field facts point to the 
formation of serpentine through introduction of 
solutions into a rock already completely crystal- 
lized to anhydrous minerals (olivine or olivine 
and pyroxene). This interputation is in better 
accord with our experimental results". 

In the hypothesis advocated by Bowen and 
Tuttle, they submit that under certain conditions 
of crustal deformation a mass of dunite or perido- 
tite may become mobilized. During its tectonic 
transport it is intruded into an aqueous environ- 
ment and acquires water (serpentinizing solu- 
tions) from the surrounding wet rocks. Under 
favorable temperature and pressure conditions, 
serpentinization of the peridotite proceeds simul- 
taneously with its transport and emplacement. 
The conditions of tectonic transport probably 



facilitate serpentinization because of granulation 
and fracturing which make the material more 
readily accessible to water. Because of its physical 
properties, the serpentine, thus formed, in turn, 
makes the mass more mobile and continued de- 
formation and intrusion is greatly facilitated. 

Based on field relationships of the dunites and 
peridotites noted during this investigation and 
those observed by previous workers, it appears 
that the tectonic transport hypothesis, as de- 
scribed by Bowen and Tuttle (1949, pp. 439-460), 
most satisfactorily accounts for the major serpen- 
tinization of the North Carolina peridotites. As 
pointed out by Bowen and Tuttle (1949, p. 456) 
if a dunite or peridotite mass was subjected to 
this action, a mass that is peripherally serpen- 
tinized but the central part of which is not ser- 
pentinized would be an expected result. As pre- 
viously noted, this type of zoning is quite common 
in North Carolina peridotites. Also, the lack of 
significant contact metamorphic effects in the 
adjacent country rock, a relationship that has 
been noted by a number of previous workers, is 
accounted for in the Bowen and Tuttle hypothesis 
by the fact that their experimental data suggests 
that the ultramafic rocks were at comparatively 
low temperature at the time of emplacement. 

Although it appears that the majority of the 
serpentinization that has affected the North Caro- 
lina peridotites took place during tectonic trans- 
port and before final emplacement, it is very un- 
likely that this is the only mode of serpentiniza- 
tion that has acted on the peridotites. Subsequent 
periods of metamorphism and granite intrusions 
have undoubtedly been responsible for the develop- 
ment of some serpentine, particularly along in- 
ternal faults and shear planes (Hunter, 1941, p. 
36). 

Sleatitization : Steatitization is that mode of 
alteration of the ultramafic rocks which results in 
the formation of talc. The process is considered by 
most recent workers to be later than serpentiniza- 
tion and that the alteration to talc was effected 
by hydrothermal solutions. 

Talc is a common constitutent of all the ultra- 
mafic rocks in North Carolina and it is derived 
from the alteration of olivine, pyroxenes and 
amphiboles. In the dunites it occurs as large dis- 
seminated pseudormorphs after enstatite and as 
microscopic envelopes around the edges of the 
olivine grains. In the saxonites and enstatolites, 
talc frequently replaces enstatite and anthophyl- 



11 



lite. Talc may develop as scales along the cleavage 
cracks of the enstatite and gradually replace it, 
forming a pseudormorph. More often, however, it 
forms irregularly distributed and oriented scales 
in the enstatite, which develop in size until the 
original mineral is replaced. In the case of the 
alteration of anthophyllite to talc, the talc usually 
develops parallel to the cleavage cracks. 

In many cases, steatitization has proceeded to 
the point where the ultramafic body is more or 
less a talcose rock, or soapstone. In some of these 
soapstone bodies, thin layers of pure, apple-green, 
foliated talc have developed along what appear to 
be local shear planes. 

A very common occurrence of talc is with ver- 
miculite and chlorite in the thin border zone of 
schistose rocks that usually envelops the ultra- 
mafic bodies. Talc is not always present in this 
zone because in some instances the envelope is 
composed entirely of chlorite. However, talc and 
vermiculite usually occur together. 

From a recent detailed petrographic and geo- 
chemical study of some selected talc-bearing ultra- 
mafic rocks in Vermont, Chidester (1962, p. 94) 
concluded that "steatitization took place contem- 
poraneously with and at essentially the same tem- 
perature as regional metamorphism, without 
notable changes in temperature during the steati- 
tization process". Chidester (1962, p. 128) further 
suggests that the steatitizing solutions were of 
a simple nature, consisting mainly of C0 2 , H 2 
and Si that were derived from rocks of sedimen- 
tary parentage during progressive metamor- 
phism. That the solutions effecting steatitization 
were independent of a magmatic source is con- 
trary to the view held by most previous workers 
who considered the steatitizing solutions to be hot 
igneous solutions derived from nearby or under- 
lying acid igneous rocks. 

As described by Chidester (1962), some of the 
characteristics of the Vermont talc-bearing ultra- 
mafic rocks have similar counterparts in many 
of the North Carolina ultramafic bodies. However, 
whether or not steatitization in the North Caro- 
lina ultramafic rocks can be attributed to similar 
processes as those that effected the Vermont ul- 
tramafics can be determined only by much more 
detailed study. 

Amphibolization : The development of amphi- 
bole is very common in the ultramafic rocks in 
North Carolina. In the dunites minute needle-like 
crystals of amphibole (usually anthophyllite) oc- 
cur disseminated throughout the mass. The 



needles are usually straight, oriented in all direc- 
tions, and penetrate several individual olivine 
grains. An increase of the amphibole needles in 
both size and number ultimately leads to the local 
development of zones composed almost entirely of 
crossed and interlocking amphibole minerals. 
Anthophyllite also occurs in the dunites as narrow 
veins that cut through the body in all directions. 

The alteration to amphibole is particularly evi- 
dent in the enstatolites. Where enstatite is present 
in the rocks, the needles of amphibole may pene- 
trate the enstatite in all directions, or develop 
parallel to the long dimension of the enstatite 
crystals. In either case, this type of alteration has 
evidently resulted in the formation of some of the 
mass-fiber asbestos deposits. 

The alteration of olivine to anthophyllite in- 
volves the loss of magnesium and iron or the ad- 
dition of silicia, whereas the alteration of enstatite 
to anthophyllite is a physical transformation as 
the two minerals have essentially the same chemi- 
cal composition. Amphibolization is a late stage 
process that took place after the individual peri- 
dotite bodies were emplaced in their present rela- 
tive positions and after any crushing or granula- 
tion effects. This is demonstrated by the fact that 
the amphibole crystals are oriented in all direc- 
tions with respect to each other and, except for 
cross fracturing, are not disturbed. 

Chloritization : Chlorite is present in the ultra- 
mafic rocks as dissiminated flakes and foliae, as 
narrow veins that penetrate the rocks in all 
directions, and as a peripheral zone that practi- 
cally always borders the peridotites. 

The alteration of olivine or enstatite to chlorite 
involves the addition of significant amounts of 
alumnia and water plus the loss of magnesium and 
iron in the case of olivine and the loss of silica 
in the case of enstatite. Dunite usually contains a 
small amount of alumnia, but not enough to per- 
mit the alteration of more than an insignificant 
part of the rock to chlorite. Thus it is evident 
that solutions originating from without must have 
been responsible for supplying the necessary 
alumina and water and removing or redepositing 
the excess magnesium and iron. 

Origin 

The ultramafic rocks have been of interest for 
many years and have been investigated by many 
able geologists. However, many questions remain 
to be answered concerning the source and manner 
of formation of peridotite, dunite and pyroxenite, 



12 



their mode of intrusion, and the manner and cause 
of alteration. 

Prior to 1900 there was considerable contro- 
versy among contemporary workers as to whether 
or not the dunites were of sedimentary or igneous 
origin (Pratt and Lewis, 1905, p. 125-137). How- 
ever, by the turn of the century, the igneous char- 
acters of the dunites had been well established 
and generally accepted. After an igneous origin 
for the ultramafics had been established, most 
workers regarded dunite and peridotite as'the 
products of direct consolidation from a magma of 
their own composition. 

Bowen (1915, p. 79-80) first pointed out that 
dunite, consisting almost entirely of olivine with 
no significant amounts of other minerals to give 
the mutual fluxing effects that ordinarily prevails 
in mineral assemblages, could exist in the com- 
pletely liquid state only above the very high 
temperature at which olivine melts (1800° C.) 
The lack of evidence that these rocks ever existed 
at such very high temperature led Bowen to con- 
clude that dunite was never liquid as such, but 
was formed by accumulation of early olivine cry- 
stals from a complex magma. Later, Bowen (1917, 
p. 237) suggested, "that when the mass of olivine 
crystals thus accumulated was subjected to the 
appropriate forces it might be intruded into other 
rocks as a solid or substantially solid mass with 
little, if any, liquid to lubricate its flow". 

Contrary to Bowen's hypothesis, Hess (1938) 
suggested that peridotites in narrow belts asso- 
ciated with strongly deformed zones of the earth's 
crust (alpine type peridotites) were derived 
from a highly aqueous ultramafic liquid approxi- 
mating serpentine in composition. He further 
suggested that such magmas were generated by 
differential fusion of the peridotite substatum un- 
der local impact of a very greatly thickened seg- 
ment of the overlying granitic crust where it was 
down folded at the onset of orogeny. The high 
concentration of water was assumed to lower the 
temperature of crystallization enough, at least in 
some instances, so that serpentine crystallized 
directly from the magma. 

Bowen and Tuttle (1949, p. 439-460) studied 
the system MgO-Si0 2 -H 2 in the laboratory at 
temperatures up to 1000° C. and pressures as 
great as 40,000 lb in 2 . The results of their investi- 
gation indicate that peridotite magma could exist 
only at temperatures well above 1000° C. even if 
the water content was 10 percent or more. Con- 
sequently, they conclude (1949, p. 455) that "the 



possibility of the formation of dunites, serpen- 
tines, and peridotites from such supposed magma 
intruded at low temperatures is definitely ex- 
cluded". The low-temperature (probably not more 
and possibly less than 500° C.) metamorphic ef- 
fects evident of the contacts of most ultramafic 
bodies appear, therefore, to require these rocks to 
have been intruded in a crystalline state. 

Based on their experimental results and estab- 
lished field relationships, Bowen and Tuttle (1949, 
p. 455-456) suggests that under certain condi- 
tions of crustal deformation dunitic and related 
material can be intruded in a completely crystal- 
line state into accessible levels of the earth. They 
picture the mass as a slowly advancing crystalline 
peridotite which is being deformed and granulated 
during transport. As it moves into the zone of wet 
rocks it absorbs water from them, especially 
peripherally, and so becomes partially serpen- 
tinized. This partial serpentinization greatly in- 
creases the mobility of the mass and facilitates 
further intrusion. 

The hypothesis advocated by Bowen and Tuttle 
on the origin and subsequent serpentinization of 
dunites, peridotites and related ultramafic rocks 
is the most compatible with the facts as known to 
date, and is generally accepted as a working hypo- 
thesis by most geologists. 

Assuming that all of the ultramafic bodies 
were at one stage in their development composed 
largely of crystalline olivine with minor amounts 
of pyroxene, it is difficult to account for all of the 
variations now present in the North Carolina ul- 
tramafic rocks only by the Bowen and Tuttle 
hypothesis. Since their emplacement, the ultra- 
mafics have been subjected to one or more periods 
of regional metamorphism and in many instances 
emanations from granitic intrusions. The effects 
of these processes on the ultramafics have not been 
studied in the light of modern petrographic and 
geochemical methods, and the exact nature of the 
changes involved is not understood at this time. 
However, many of the local variations in degree 
of alteration and the local development of antho- 
phyllite, vermiculite, chlorite, talc and corundum 
are the result of subsequent metamorphism and/or 
granitic intrusive activity. 

Age 

A definite age for the ultramafic rocks has not 
been established, but certain relationships have 
been noted which serve to restrict their age. First, 
they are intrusive only into the gneisses and 



13 



schists that Keith (1903) mapped as Carolina 
gneiss and Roan gneiss, and which have been 
established by radiometric age determinations to 
be Precambrian in age. Also, at a number of places 
mica pegmatite and alaskite are intrusive into 
the ultramafic rocks. In the Spruce Pine district, 
these pegmatites have been dated radiometrically 
at 350 million years (Kulp and Eckelmann, 1962). 
Thus, the ultramafics are younger than the 
gneisses and schists but older than the pegmatites. 
Keith (1903) considered the ultramafics to be 
"Archean" (Precambrian) in age, but Pratt and 
Lewis (1905, p. 159) classed them as Paleozoic 
in age. Recent detailed geologic mapping in the 
Spruce Pine district and the Grandfather Moun- 
tain area still leaves the question of the age of the 
ultramafics unanswered. Brobst (1962) classed 
them as Precambrian (?) whereas, Bryant (1962) 
classed them as Middle or Lower Paleozoic (?). 
The fact that many bodies of ultramafic rock oc- 
cur near, but nowhere intrude rocks of the Ocoee 
series (Upper Precambrian) seems to be, in the 
writers' opinion, a point in favor of a Precam- 
brian age for the ultramafic rocks in North Caro- 
lina. 

ASBESTOS DEPOSITS 

Mineralogy and Geologic Occurrence 

Asbestos is a commercial term applied to sev- 
eral naturally fibrous minerals that are used pri- 
marily because of their fibrous character and other 
qualities such as resistance to heat and acid. 
Chrysotile is the most important commercial va- 
riety and constitutes about 95 percent of the total 
world production. Other varieties of asbestos in- 
clude tremolite, actinolite, crocidolite, amosite and 
anthophyllite. All of these minerals vary in chemi- 
cal and physical properties and have different 
modes of occurrence. 

Chrysotile: Chrysotile (H 4 Mg 3 Si 2 9 ) is a 
fibrous form of the mineral serpentine. It occurs 
most commonly as cross fiber veins that range 
from a fraction of an inch to over six inches in 
width. Fibers of good quality are silky, highly 
flexible and have a high tensile strength. Almost 
all of the commercially valuable deposits occur as 
cross-cutting, discontinuous veins in massive ser- 
pentine bodies that have been derived from the 
alteration of peridotite. A relatively small district 
in the province of Quebec, Canada, contains 
numerous rich chrysotile asbestos deposits. These 
deposits are associated with a northeast-trending 



belt of serpentinized peridotite bodies. Approxi- 
mately one-half of the worlds annual production 
of asbestos comes from this district. 

Chrysotile also occurs in thin alteration zones 
in dolomite or dolomitic limestone along contacts 
with basic igneous intrusive rocks. In places, 
chrysotile of excellent quality is found in this en- 
vironment. However, the ore zones are usually 
rather narrow and only those deposits of unusual 
fiber length can be profitably mined. 

Deposits of this type occur at several places in 
Arizona and have supplied most of the domestic 
production of long fiber chrysotile (Stewart, 
1955). 

Chrysotile asbestos is reported to occur at sev- 
eral places in North Carolina in association with 
the ultramafic rocks. Several of these localities 
were examined during this investigation, but the 
presence of chrysotile could not be confirmed. If 
chrysotile is associated with any of the ultramafic 
rocks in North Carolina, it occurs in very minor 
amounts and is very likely of no commercial sig- 
nificance. 

Amphibole asbestos: All varieties of asbestos 
other than chrysotile belong to the amphibole 
group of minerals and are collectively referred 
to as amphibole asbestos. The amphiboles are a 
complex series of silicate minerals that are char- 
acterized by perfect prismatic cleavage with 
angles of 50° and 124° between the cleavage 
planes. The only amphibole minerals that occur 
in asbestiform masses are tremolite, actinolite, 
crocidolite, amosite and anthophyllite. 

All of the asbestiform amphiboles contain iron 
and with the exception of crocidolite contain mag- 
nesium. Anthophyllite is distinguished from trem- 
olite and actinolite by the absence of calcium, and 
crocidolite from the other asbestiform amphiboles 
by the presence of a notable amount of sodium. 
Chemically, tremolite and actinolite are very 
closely related. The replacement of one element by 
another is a prevalent characteristic of the amphi- 
bole asbestos minerals. This variation in composi- 
tion results in corresponding changes in their 
physical properties and causes somewhat erratic 
and unpredictable physical characteristics in some 
amphibole asbestos ores from different localities 
(Bowles, 1955, p. 3) . 

Tremolite: Tremolite (Ca 2 Mg 5 Si 8 2 2(0H 2 ) is 
one of the most common varieties of amphibole 
asbestos. It usually consists of gray to white silky 



14 



fibers that are sometimes as much as a foot or 
more in length. The fibers are coarser and much 
weaker than chrysotile, but fibers of considerable 
strength and flexibility are occasionally found. 
Tremolite asbestos occurs most commonly as slip- 
fiber veins in shear zones. It is found in a variety 
of host rocks, but most of the commercial deposits 
occur in ultramafic rocks derived from dunite and 
peridotite. 

Tremolite is commonly present in the ultramafic 
rocks in North Carolina, occurring most often as 
long slender needles that penetrate the other 
minerals in all directions. However, it has not 
been found in commercial quantities in North 
Carolina. 

Actinolite: Actinolite (Ca 2 (Mg,Fe) 5 (Si 4 O u ) 2 
OHo) is similar to tremolite, but contains iron in 
place of some of the magnesium. Actinolite asbes- 
tos is commonly green or grayish green and the 
fibers are quite weak and brittle. It is similar to 
tremolite in occurrence and is of very little value 
as a commercial asbestos. 

Actinolite, like tremolite, is widespread in the 
ultramafic rocks in North Carolina, but there are 
no known localities where this type of amphibole 
asbestos occurs in significant quantities. 

Crocidolite: Crocidolite (Na 6 Fe 1 oSi 1 c04o(OH) 2 ) 
is the fibrous form of the amphibole riebeckite. It 
is a beautiful, highly fibrous mineral that has a 
very silky luster and a dull lavender color. It is 
commonly referred to as blue asbestos. Its fibers 
are flexible and stronger than chrysotile, but 
somewhat coarser. The principal source of cro- 
cidolite asbestos is the Union of South Africa. 
There, it occurs as thin, cross-fiber veins in iron- 
rich sedimentary rocks (Bowles, 1955, p. 37). 
Smaller amounts are produced in Australia and 
Bolivia. There are no known commercial deposits 
of crocidolite in the United States. 

Amosite: Amosite (FeMg) 7 Si 8 22 (OH) 2 ) is 
a fibrous modification of the monoclinic amphi- 
bole grunerite. It may contain as much as 40 per- 
cent iron oxide and has been classed as a high- 
iron anthophyllite. However, it is monoclinic in 
crystallization and, therefore, not a true antho- 
phyllite (Bowles, 1955, p. 2). It is white to 
yellowish-gray in color and consists of long, fairly 
strong fibers. Amosite is mined only in South 
Africa and occurs in isolated cross-fiber veins in 
the same host rock as crocidolite asbestos. 

Anthophyllite: Anthophyllite asbestos (Mg 7 Si 8 



22 (OH) 2 ) is the fibrous form of the orthorhom- 
bic amphibole anthophyllite. The fibers are char- 
acteristically short, only slightly flexible and have 
a low tensile strength. Unweathered anthophyl- 
lite is greenish-gray to gray, but upon weathering 
the fibers become brownish-white. Most commer- 
cial anthophyllite asbestos occurs as mass-fiber 
deposits associated with altered dunites and re- 
lated ultramafic rocks. It also occurs in cross-fiber 
veins and slip-fiber veins. Anthophyllite asbestos 
has been mined in a number of countries through- 
out the world. However, the principal domestic 
sources are found in Georgia and North Carolina. 

Uses 

Asbestos is a unique mineral, and because of its 
fibrous character and resistance to heat and chemi- 
cals it has many specialized uses for which there 
are no satisfactory substitutes. On the basis of 
use, asbestos falls into two principal classes, spin- 
ning and nonspinning fiber. Only the longer fibers 
of chrysotile and crocidolite qualify as spinning 
fiber. Nonspinning fiber comprises the shorter 
grades of chrysotile and crocidolite and both the 
long and short fiber grades of amosite, anthophyl- 
lite and other amphibole varieties. 

Spinning fibers posses the necessary strength 
and flexibility that allows them to be spun, in 
much the same manner as cotton and wool, into 
textile products such as cloth, yarn, tape, etc. The 
asbestos fabrics are used extensively for lagging 
cloth, brakeband linings, clutch facings, safety 
clothing, packing, gaskets and numerous other 
products in which heat insulating, fireproofing 
and heat resistant properties are required. 

Nonspinning asbestos fibers of both the chryso- 
tile and amphibole variety are used in hundreds 
of products in numerous industries. Large quan- 
tities of the shorter grades of asbestos are used 
in all types of fireproofing and heat insulating 
products in the building trade. A few of the most 
common uses include roofing shingles, pipe cover- 
ing, wallboard, millboard, water and sewer pipes, 
and wall and floor tiles. 

Anthophyllite asbestos has a low tensile 
strength and is therefore, not used in products in 
which the fiber must impart strength to the 
product. However, it is superior to all other varie- 
ties of asbestos in resistance to heat and acid and 
is well suited for numerous products in which 
these properties are of prime importance. 

The main uses of anthophyllite are for chemical 
filters; in plastic cement to cover boilers, pipes 



15 





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and furnaces ; as a filler in rubber, battery boxes 
and molded electronic insulation products; for 
welding rod coatings; and as an admixture in 
cement and plastic flooring, accoustical and other 
wall plasters, and stucco (Bowles, 1955, p. 14). 

Character and Classification 
of North Carolina Deposits 

General Statement: Various types and quanti- 
ties of asbestiform minerals are associated with 
the ultramafic rocks in North Carolina. Chrysotile 
asbestos is reported to occur at several places. 
However, some of these localities were examined 
during this investigation but the presence of 
chrysotile could not be confirmed. If chrysotile is 
associated with any of the ultramafic rocks in 
North Carolina, it occurs in very minor amounts 
and is very likely of no commercial significance. 
Tremolite and actinolite are also very commonly 
associated with the ultramafic rocks, but they oc- 
cur in very limited amounts and most often are 
not in a fiberous form. 

Anthophyllite is the only asbestiform mineral 
found in North Carolina that occurs in sufficient 
quantity and quality to be considered an asbestos 
ore. Based on the arrangement of the fibers in 
respect to the wall rock and to each other, three 
types of anthophyllite asbestos are recognized. 
These types are referred to as cross-fiber veins, 
slip-fiber veins and mass-fiber deposits. The mass- 
fiber deposits are further divided into peripheral 
zones and oval shaped bodies composed mostly of 
anthophyllite and enstatite. 

Cross-fiber veins: Cross-fiber anthophyllite oc- 
curs in veins, with the fibers arranged parallel 
to each other and perpendicular to the walls of 
the vein. Although not the most productive in 
terms of tonnage, cross-fiber anthophyllite is by 
far the most common mode of occurrence for 
asbestos in North Carolina. The veins are present 
in rocks that range from dunite to soapstone in 
composition and are present throughout the length 
of the ultramafic belt. 

The veins range from a fraction of an inch up 
to 8 or 10 inches wide, but are most often between 
1 and 3 inches wide. They cut through the enclos- 
ing rock in all directions, and it is not uncommon 
for one vein to intersect another, usually at near 
right angles. Many cross-fiber veins are composed 
of practically pure anthophyllite asbestos. This is 
particularly true of the veins associated with 
dunite. In the more altered ultramafic rocks, talc 
is commonly associated with the anthophyllite and 



in some instances talc has almost completely re- 
placed the anthophyllite. 

The contact between the' vein material and en- 
closing rock is usually quite sharp. In many cases, 
differential movement between the vein material 
and the enclosing rock has distorted the orienta- 
tion of the fibers. Where differential movement 
has taken place, the fibers in the outer portion of 
the vein have been sheared and rearranged so 
that they are more or less parallel to the vein 
walls. The fibers in the interior of the vein may 
be distorted or slightly curved, but remain es- 
sentially perpendicular to the vein walls. 

At least four attempts have been made in the 
past to mine cross-fiber vein deposits. In each case 
the ore was evidently of excellent quality, but the 
limited quantity present in any one deposit pre- 
cluded any extensive or long range mining opera- 
tion. 

Slip-fiber veins: Slip-fiber asbestos also occurs 
in veins, but in this case the fibers are arranged 
approximately parallel to the enclosing walls. As 
there are all gradations in orientation of fibers 
between cross-fiber and slip-fiber, it is generally 
concluded that cross-fiber is converted to slip- 
fiber by differential movement of the wall rock 
with respect to the vein material. Except for the 
orientation of the fibers with respect to the wall 
rock, slip-fiber anthophyllite asbestos is similar to 
cross-fiber in character and mode of occurrence. 
However, slip-fiber asbestos is not nearly as com- 
mon in the North Carolina ultramafic rocks as is 
cross-fiber asbestos. 

One of the most interesting features of the slip- 
fiber veins are the unusually large pieces of pure 
anthophyllite asbestos that are associated with 
them. Pieces 1 to 2 feet in length and up to 4 
inches in diameter are not uncommon, and some 
pieces up to 3 feet in length and 6 inches in 
diameter have been found. 

Slip-fiber asbestos has accounted for only a very 
small percentage of the total asbestos mined. Most 
of it has been recovered incidental to mining for 
cress-fiber and mass-fiber ore. 

Mass-fiber deposits: Mass-fiber ore differs from 
cross- and slip-fiber ore in that it does not occur 
in veins, but forms the body of the rock. The 
fibers are arranged in bundles of varying size that 
are oriented in all directions in respect to each 
other. Also, in some mass-fiber deposits the antho- 
phyllite is arranged in distinct, cone shaped or 
radial structures. 



17 



Two distinct types of mass-fiber ore are asso- 
ciated with the ultramafic rocks in North Caro- 
lina. Based on their mode of occurrence these two 
types of ore are classed as (1) peripheral zones, 
and (2) individual ultramafic bodies composed 
mostly of anthophyllite and enstatite. 

Peripheral zones: It has been previously 
pointed out that the ultramafic rocks are char- 
acteristically enclosed by a relatively thin zone of 
schistose talc, chlorite and vermiculite. This zone 
ranges from a few inches to several feet wide and 
pinches and swells around the ultramafic body. 
Usually one mineral prevails over the others. In 
some cases the zone is composed almost entirely of 
talc, and in others either vermiculite or chlorite 
predominates. Mass-fiber anthophyllite asbestos 
is often associated with this peripheral zone of 
alteration. 

Although a peripheral zone of schistose rock is 
characteristic of all the ultramafic rocks, the 
presence of a well developed zone of mass-fiber 
asbestos is much less common. In a few instances, 
a peripheral zone of mass-fiber asbestos is asso- 
ciated with dunite. However, most of the deposits 
which have been mined for asbestos are associated 
with the smaller and more thoroughly altered 
bodies of peridotite and enstatolite. Where present, 
the zone of mass-fiber asbestos usually lies adja- 
cent to the mass of the ultramafic body and is 
separated from the country rock by a thin layer of 
schistose talc and/or vermiculite. The contact be- 
tween the asbestos zone and the outside layer of 
schistose rock is usually relatively sharp and uni- 
form. The contact between the asbestos and the 
mass of the ultramafic body is also sharp, but at 
times quite irregular. The width of the asbestos 
zone ranges from a few inches up to as much as 
6 to 8 feet. However, the average width is from 1 
to 2 feet. Some of the peripheral zones of asbestos 
are very uniform in width, although it is not un- 
usual for a relatively wide zone to narrow rapidly, 
both along strike and at depth. 

The mass-fiber asbestos associated with the 
peripheral zone varies in color from grayish white 
to various shades of mottled buff and light-brown. 
Ore that lies on and near the surface is usually 
badly stained by iron oxide and quite soft. The 
deeper ore is more compact, but the fibers can be 
easily separated by hand. Much of the mass-fiber 
ore is very coarsely crystalline material composed 
of interlocking bundles of fibers that are as much 
as 2 to 3 inches in length. Other mass-fiber ore is 
less coarsely crystalline and in some deposits the 



fibers are arranged in distinct radial form. 

The peripheral zones of mass-fiber ore are com- 
posed predominantly of asbestos. Anthophyllite 
usually makes up more than 85 percent of the 
rock and talc is the only other mineral present in 
significant amounts. Trace amounts of chlorite, 
magnesite and magnetite are usually present. 

Because of the high percentage of asbestos 
present in the mass-fiber deposits, the high ratio 
of ore recovery to total amount of rock mined, 
and the relatively simple mining methods em- 
ployed, most of the past production of North Caro- 
lina asbestos has come from peripheral zone mass- 
fiber deposits. 

Anthophyllite-enstatite bodies: Many of the 
ultramafic bodies occur as small, pod shaped 
masses that are composed predominantly of vary- 
ing percentages of enstatite, anthophyllite and 
talc. These rocks were described by Lewis (1896, 
p. 25) and referred to as enstatite rock. Later, 
Pratt and Lewis (1905, p. 30) proposed the term 
enstatolite for these rocks and they have since 
been referred to by that name. Although Lewis 
(1896, p. 26) and Pratt and Lewis (1905, p. 30) 
described enstatolite as being composed essential- 
ly and almost exclusively of enstatite and talc 
derived from the alteration of enstatite, many 
of the rock masses previously referred to as en- 
statolite contain equal or greater amounts of an- 
thophyllite and talc than enstatite. In these cases 
the term enstatolite is somewhat misleading. How- 
ever, as most of the anthophyllite and talc present 
in these rocks was evidently derived from the 
alteration of original enstatite, the term is re- 
tained in this report in reference to some of the 
mass-fiber anthophyllite bodies. 

As previously stated in the section of this report 
dealing with petrography, the enstatite usually 
occurs as large, bladed, interlocking crystals that 
are oriented in all directions in respect to each 
other. In some deposits, in excess of 50 percent 
of the rock is composed of relatively unaltered 
enstatite. However, quite frequently the enstatite 
has undergone considerable alteration. In such 
cases, the alteration products consist almost en- 
tirely of anthophyllite and talc along with minor 
amounts of chlorite. It is these more thoroughly 
altered enstatolite bodies that contain significant 
amounts of mass-fiber anthophyllite asbestos. The 
degree of alteration of the individual enstatolite 
bodies varies considerably within a single mass 
and from one deposit to another. Consequently, 
the percentage of anthophyllite present is also 



18 



quite variable. In some deposits, the replacement 
of enstatite by fibrous anthophyllite and talc is 
practically 100 percent complete; whereas, in 
others anthophyllite is present in amounts of 20 
percent or less. 

The mass-fiber ore associated with enstatolite 
bodies occurs in two distinct forms. The most com- 
mon variety is that in which the anthophyllite 
fibers have developed parallel to the long direc- 
tion of the enstatite crystals and assumed the 
form of the original rock mass. The asbestos oc- 
curs in broad, flat interlocking bundles of fibers 
that are oriented in all directions in respect to 
each other. One of the most striking features of 
this type of ore are the unusually large crystals 
(secondary after enstatite) of fibrous anthophyl- 
lite present in some of the deposits. Interlocking 
crystals up to 6 inches long and 1 to 2 inches wide 
are common and occasionally crystals that ap- 
proach 1 foot in length are present. However, the 
average length is between 1 and 3 inches. Fresh, 
unweathered ore in bluish gray to gray in color, 
massive and quite tough. The fibrous character of 
the fresh ore is not readily apparent, but the ends 
of the variously oriented crystals become fibrous 
when struck with a hammer or otherwise broken. 

Less common but equally distinct is the variety 
of mass-fiber ore in which the fibers occur as a 
mass of interlocking cones. The fibers radiate 
from a common center and vary from a 14 inch 
up to about 1 inch in length. In some cases, the 
apex of an individual cone is as much as 14 inch 
higher than the perimeter, and in others the cones 
are almost flat. Individual, well shaped cones are 
not common because of mutual interference dur- 
ing development, but the tendency toward radial 
and cone structure is quite evident in all of the 
ore. 

The ore varies from light, bluish gray to yellow- 
ish gray in color and is massive, compact and 
quite tough. The fibers are generally short and 
splintery. Talc is the most commonly associated 
mineral and is developed parallel to the asbestos 
fibers and fills the spaces around and between the 
cones. 

Origin of anthophyllite asbestos: In discussing 
the origin of the North Carolina anthophyllite 
asbestos deposits, two aspects of the problem have 
to be considered. First, is the origin of the amphi- 
bole mineral (anthophyllite), and second is the 
development of the fibrous or asbestos form. 

In the case of the origin of the amphibole min- 
eral, it may be stated that anthophyllite is not 
the result of original crystallization, but has 



developed from secondary processes. The altera- 
tion of dunite to anthophyllite is quite common, 
and in thin sections olivine can be seen in all 
stages of alteration to anthophyllite. Some sec- 
tions show only a few slender needles of antho- 
phyllite that are scattered throughout the ground- 
mass of olivine. The needles are usually straight, 
show no preferred orientation and a single crys- 
tal often penetrates several olivine grains. At the 
other extreme, some sections are composed almost 
entirely of crossed and interlocking anthophyllite 
crystals with only small remnants of the original 
olivine grains left. Thus, it is apparent that dun- 
ite and perdiotite may alter to mass-fiber asbestos. 

As previously noted, many of the dunites ex- 
hibit a definite zoning. This zoning is character- 
ized by a core of nearly pure olivine which shows 
little, if any, effects of serpentinization. The core 
is surrounded by a zone of serpentinized olivine 
which in turn is surrounded by an outside zone 
composed principally of amphibole minerals. An- 
thophyllite is the predominant amphibole but 
minor amounts of tremolite and actinolite are also 
present. This type of amphibolization has evident- 
ly resulted in the development of the peripheral 
zone type of mass-fiber asbestos. 

The alteration of a pyroxene mineral to an 
analogous amphibole is a common alteration and 
is generally indicative of metamorphic or other 
geologic processes which produce unstable physi- 
cal conditions. The alteration of pyroxene (en- 
statite) to amphibole (anthophyllite) is well ex- 
emplified in the enstatolites. This process can be 
observed in all stages of development, and it is 
quite obvious that the mass-fiber asbestos deposits 
associated with enstatolite have resulted from 
the alteration of enstatite to anthophyllite. 

Cross- and slip-fiber veins of anthophyllite as- 
bestos are also unquestionably of secondary ori- 
gin, but they do not reveal any evidence of having 
been derived directly from some other mineral 
as is the case in the mass-fiber varieties. The veins 
were evidently developed in pre-existing frac- 
tures by solutions moving through the ultramafic 
rocks. Many of the cross-fiber veins are from 2 
to 6 inches wide and it is very improbable that 
veins of this width represent open fissures. Most 
likely, the fissures were minute fractures in the 
rocks and the cross-fiber veins were formed at 
the expense of the wall rock by the action of the 
solutions on the wall rock. Subsequent minor re- 
adjustments in the rock mass caused the local 
formation of slip-fiber veins. 

The exact nature of the formation of the frac- 



19 



tures along which the solutions moved is un- 
known. They probably are the result of adjust- 
ment to strain, or slight changes in volume, 
brought about during one or more periods of 
regional metamorphism and/or igneous intrusion 
after the ultramafics were implaced in their 
present position. 

From the foregoing, it is obvious that the an- 
thpohyllite asbestos deposits are the end result 
of perhaps diverse, and certainly complex, geol- 
ogic processes. Enough detail information is not 
available at this time to make anything more 
than general statements concerning the origin of 
these deposits. However, field relationships and 
limited laboratory work substantiate the fact that 
anthophyllite was not an original mineral consti- 
tuent of the ultramanc rocks, but was formed by 
secondary processes. The ultramanc rocks in 
North Carolina have been subjected to one or 
more periods of regional metamorphism and, in 
many instances, to igneous activity. It is not 
clear which of these processes are more closely 
related to the development of anthophyllite. The 
fact that anthophyllite is present in various forms 
in rocks that range from dunite to soapstone in 
composition, and is present throughout the entire 
length of the peridotite belt, seems to indicate a 
metamorphic origin. On the other hand, the in- 
timate relationship between some of the asbestos 
deposits and pegmatite dikes, quartz veins, corun- 
dum, chlorite, vermiculite and tourmaline, offer 
strong evidence that hydrothermal solutions were 
responsible for the development of anthophyllite. 
This suggests that all of the anthophyllite cannot 
be attributed to any one process, but is the result 
of a combination of factors that involve both met- 
amorphism and hydrothermal solutions. 

The development of the fibrous or asbestos form 
of anthophyllite seems to be largely a physical 
phenomenon directly related to weathering. This 
relationship has been noted by many previous 
workers at asbestos deposits throughout the 
world. Hopkins (1914, p. 106) further suggests 
that the fibrous form of amphibole is mainly the 
result of inherent abnormal development of pris- 
matic cleavage, but becomes more pronounced on 
weathering. 

That a direct relationship exists between de- 
gree of fiberization and extent of weathering is 
also quite apparent in the asbestos deposits in 
North Carolina. This is particularly true in the 
peripheral zone mass-fiber deposits and the an- 
thophyllite-enstatite mass-fiber deposits. In fact, 
it is common practice to allow ore mined from 



some of these mass-fiber deposits to remain in a 
stockpile exposed to the elements for a year or 
more. This is reported to soften the ore consider- 
ably, which results in easier milling and increased 
fiber length recovery. 

History of Mining and Production: Between 
1870 and about 1900, North Carolina was a 
leading producer of domestic corundum. During 
this period, mining operations were carried on at 
a number of the ultramafic bodies and numerous 
others were prospected for corundum. Asbestos 
was noted at practically all of these mines and 
prospects, but little attention was paid to it by 
the corundum miners. The first recorded attempt 
to mine asbestos in North Carolina was about 
1901. A serpentine deposit near North Wilkesboro 
on the land of J. B. Church was worked by means 
of an open cut 100 feet long and 1 to 35 feet deep. 
The asbestos was reported to be of the chrysotile 
variety and occurred in veins that varied from *4 
to 2 inches in width (Pratt, 1902, p. 98). This 
operation lasted only a short time and no pro- 
duction was recorded. 

From about 1910 until about 1925 considerable 
prospecting for amphibole asbestos was carried 
out in Ashe, Avery, Caldwell, Jackson, Macon, 
Mitchell, Avery and Yancey counties, and a num- 
ber of favorable prospects were located. How- 
ever, the only production recorded for this period 
was in 1919 when North Carolina ranked third 
nationally in the production of asbestos. All of 
this production came from one producer, N. C. 
McFalls, Cane River, Yancey County, and con- 
sisted entirely of anthophyllite asbestos (Drane 
and Stuckey, 1925, p. 34). 

In 1925, the National Asbestos Company built 
a plant at Minneapolis, Avery County, to process 
anthophyllite asbestos ore from the Frank de- 
posit, located 2.5 miles south of Minneapolis on 
the North Toe River. This mine and mill operated 
on a small scale until the late 1930's and both 
have been inactive since that time. Another plant 
was built at Norton, Macon County, at about the 
same time as the one at Minneapolis. However, if 
it ever processed any ore it was only a very limit- 
ed amount. 

Between 1930 and 1947 a number of mining 
companies and individuals mined small to moder- 
ate amounts of anthophyllite asbestos from de- 
posits in Avery, Yancey, Mitchell, Jackson and 
Macon counties. From 1941 to 1945, W. T. Hippey 
mined several thousand tons of ore from the Hip- 
pey mine near Micaville, Yancey County. About 



20 






1941 the Industrial Minerals Corporation began 
mining at the Blue Rock mine a few miles south 
of Micaville, Yancey County, and for several years 
produced relatively large tonnages of high grade 
mass-fiber anthophyllite asbestos which was pro- 
cessed at the company's mill at Spruce Pine. The 
Blue Rock mine was later controlled by the Min- 
ing and Milling Corporation of America and pro- 
duction was reported for 1953 and 1954. The mine 
has been worked intermittently for the past sev- 
eral years by the Blue Rock Mining Corporation 
of Illinois. 

The most consistent and largest producer of 
anthophyllite asbestos in North Carolina is the 
Powhatan Mining Company of Baltimore, Mary- 
land. This company has mined asbestos in North 
Carolina more or less continuously since 1918 
(Fred A. Mett, personal communication). Pro- 
duction has consisted mainly of the peripheral 
zone type of high-grade, mass-fiber ore. Deposits 
that have yielded from considerably less than a 
hundred to several thousand tons of ore have been 
prospected and mined in practically all of the 
counties in which the peridotites occur. Mines that 
have recently or are currently being mined by this 
company, include the Kilpatrick mine, Transyl- 
vania County; the Asbestos and Brockton mines, 
Jackson County; and the Newdale mine, Yancey 
County. In the past, all of the ore has been shipped 
to the company's processing plant at Baltimore, 
Maryland. 

Mining Methods : Because of the size, shape and 
occurrence of the deposits, all of the asbestos in 
North Carolina has been mined by relatively sim- 
ple open cut methods. In many instances, the 
ore was recovered entirely by hand labor using 
picks, shovels and wheelbarrows. More recent 
mining operations utilize bulldozers, front-end 
loaders, draglines and pneumatic drilling equip- 
ment. 

Most of the ore mined to date has been the 
peripheral zone type of mass-fiber asbestos. Pits 
developed in this type of ore follow the contact 
zone between the ultramafic body and the coun- 
try rock and are therefore irregular in shape. Ore 
near the surface that has been exposed to weather- 
ing is quite soft and can be readily dug with a 
pick or dragline. As the pit is deepened the ore 
becomes fresh, massive rock that has to be brok- 
en by explosives. When this becomes necessary 
the drilling is done with pneumatic hand drills 
and dynamite is used to charge the holes. The 
mass-fiber ore is not hard, but is exceedingly 



tough and blasting is not very effective except 
when a good bench is present. Secondary breakage 
is often necessary and this is usually done with 
sledge hammers or dynamite. 

Open pit mines developed in the peripheral zone 
deposits are limited in depth. As the pit is deep- 
ened the peripheral zone begins to dip underneath 
the ultramafic body and timbering becomes nec- 
essary in order to keep the pit open. Also, the 
schistose contact zone is quite unstable which 
makes hazardous working conditions. Therefore, 
the development of the pit is usually limited to 
the depth at which a dragline can effectively 
operate. 

The hard or mass-fiber ore associated with the 
enstatolite bodies is mined by standard bench 
type quarry methods. This type of ore differs from 
the others in that much if not all of the body can 
be utilized as ore and the mining does not have to 
be as selective. This allows larger amounts of ore 
to be mined by more efficient methods. 

Reserves: Although accurate records are not 
available to substantiate the claim, it is conser- 
vatively estimated that total past production of 
high grade, anthophyllite asbestos is at least 
100,000 tons. Owing to the nature of the deposits 
it would be virtually impossible to make a reason- 
able estimate of the total reserves of anthophyl- 
lite asbestos in North Carolina. However, based 
on observations made during this investigation, it 
appears that there is a minimum of 100,000 tons 
of asbestos in sight. This includes only the hard 
mass-fiber ore associated with the enstatolite. 
Reserves of peripheral zone mass-fiber ore and 
cross- and slip-fiber ore are unknown. 

DESCRIPTION OF 
MINES AND PROSPECTS 

SPRUCE PINE AREA 

The Spruce Pine area lies in the northeastern 
section of the Blue Ridge Province in North Caro- 
lina and includes parts of Avery, Mitchell and 
Yancey counties. Numerous bodies of ultramafic 
rocks are known to occur in the area and many 
of them have been prospected and mined for as- 
bestos. Mass-fiber anthophyllite asbestos is cur- 
rently being mined from the Blue Rock mine and 
the Newdale mine, both of which are located in 
Yancey County. 

Avery County 
Burleson mine: This mine is located 1200 feet 

21 



west of SR (State Road) 1117, 2.5 miles south- 
west of Newland and 0.6 mile north of Mt. Pleas- 
ant church. It is on the east side of a south flowing 
tributary to Hughes Creek. 

This ultramafic body consists of two isolated 
outcrops of enstatolite. The larger body crops out 
directly behind the Burleson house and is the one 
in which the mine was developed. The other out- 
crop is located about 75 feet northwest of the 
larger outcrop and is an oval shaped body that is 
about 15 feet wide and 30 feet long that stands 
about 10 feet above the surrounding ground level. 
A traverse around both outcrops failed to reveal 
any contact relationships and the true dimensions 
of the body are unknown. However, it appears 
that the body is about 100 feet long and 50 to 75 
feet wide, the long dimension lying in a northwest- 
southeast direction. Outcrops are poor, but the 
adjacent country rock appears to be predominant- 
ly hornblende gneiss, and garnetiferous-muscovite 
gneiss that strikes N 20° E and dips 80° SE. 

Both outcrops of enstatolite are well exposed 
and are composed predominantly of large inter- 
locking crystals of anthophyllite and enstatite. 
Talc is also present in significant amounts. As 
exposed in the face of the quarry, layering is a 
distinct feature. The individual layers range from 
less than two feet up to 5 feet in thickness and 
have an apparent dip of 15° northeast. The body 
is cut by numerous veins of cross-fiber anthophyl- 
lite that vary from a fraction of an inch up to 
two inches wide. Most of the veins are oriented 
perpendicular to the layering. 

This mine was worked by the Powhatan Mining 
Company about 1958 and a small, but undeter- 
mined amount of mass-fiber asbestos was recov- 
ered. Also, a small amount of slip-fiber asbestos 
was mined from a small pit at the southeast end 
of the body. The mine workings consist of a verti- 
cal face about 15 feet high and 30 to 40 feet wide. 
The best grade ore is reported to have been recov- 
ered from the northeast side of the face. 

Frank mine: A large dunite body occurs just 
south of Frank, about 2.5 miles south of Minnea- 
polis and 4.3 miles southwest of Newland. The 
North Toe River flows adjacent to and across part 
of the formation. The dunite body is about 1400 
feet long and averages about 400 feet in width, 
the long dimension lying in an east-west direction. 
It is well exposed in two barren hills on the south 
side of the river. The larger and western-most hill 
rises over 300 feet above river level. 

Slip- and cross-fiber anthophyllite asbestos 



which occurs in the contact zone and in many of 
the interior faults (Hunter, 1941, p. 43) was pro- 
duced intermittently for several years from this 
deposit. The deposit has not been worked for 
asbestos during the past 20 years, but according 
to Bryson (1928, p. 27) the mining was done 
chiefly by the open pit method although two small 
tunnels were sent into the hillside to determine 
the depth of the ore. The asbestos ore was hand 
picked at .the mine and hauled by truck to a small 
processing plant at Minneapolis. At the plant, 
which had a daily capacity of 30 tons, the ore 
was crushed, fiberized and screened. 

Other prospects: Other small ultramafic bodies 
that have been prospected for anthophyllite asbes- 
tos are located on the south side of Hawshore 
Mountain and on the northeast side of Big Elk 
mountain south of Hughes. 

Mitchell County 

J. H. Pannell prospect: A small peridotite body 
occurs on the south side of SR 1199, about 1 mile 
southeast of Bakersville. The deposit crops out 
on the nose of a low hill south of White Oak Creek 
and within 50 feet of the road. 

Hunter (1941, p. 57) reported the presence of 
chrysotile asbestos as occurring in this deposit as 
seams up to 6 inches thick and as individual fibers 
and clusters of fibers penetrating individual oli- 
vine grains. Several specimens of a finely fibrous 
anthophyllite asbestos associated with serpentine 
were collected during this investigation, but the 
presence of chrysotile asbestos could not be con- 
firmed. 

Soapstone Branch prospect: This deposit is lo- 
cated on the west slope of Cane Creek Mountain, 
1200 feet northwest of Rube Green Top at the 
headwaters of Soapstone Branch. It is about 2 
miles northeast of Hawk, Mitchell County and 
2.5 miles northwest of Plumtree, Avery County. 
It is situated in a very inaccessible area and can 
be reached only on foot. 

Although this deposit has not been prospected 
and its value as an asbestos prospect is unknown, 
it is of interest because of the relationship of the 
various rock types exposed. The peridotite body is 
about 400 feet long and 100 feet wide, the long 
dimension lies in a north-south direction. It stands 
up in prominent, massive outcrops above the 
surrounding rocks and two pinnacle shaped out- 
crops at the north end of the body are about 30 
feet high. The south end of the body is composed 



22 



Figure 3 




Scale 



0.5 



2 Miles 

2 



ULTRAMAFIC BODIES 



MICAV1LLE 7.5' QUAD- 



MAP SHOWING LOCATION OF 
ASBESTOS MINES IN YANCEY CO., NC. 



N 



Figure 3. Map showing location of asbestos mines in Yancey 
County, North Carolina. 



23 



mainly of talcose soapstone that is deeply weath- 
ered and pitted. In the middle section, the body 
consists essentially of serpentinized olivine. 

At the north end of the body, along the west 
and northwest side, three alteration zones are 
distinctly displayed. The outermost zone is be- 
tween 2 and 3 feet wide and consists of coarse- 
grained chlorite enterlayered with anthophyllite 
and talc. The middle zone varies in width, but does 
not exceed about 5 feet and is composed mostly of 
amphibole minerals. The outer plus or minus 1 
foot of this zone contains extremely large radial 
shaped masses of anthophyllite and long-bladed 
crystals of tremolite and/or actinolite. Also, con- 
siderable amounts of talc are present. The inner- 
most zone is composed mainly of anthophyllite 
and talc. The anthophyllite occurs in radial and 
cone shaped masses which are up to an inch in 
diameter. Talc occurs dissiminated throughout the 
anthophyllite as blade like crystals and masses. 
This zone varies in width from a few feet up to 
15 feet and can be traced for about 100 feet along 
the west side of the body. All three of these zones 
are very distinct and appear to be in a sharp 
contact. 

The interior of the body adjacent to the altera- 
tion zones is composed of layered, serpentinized 
dunite that contains small chromite crystals dis- 
siminated throughout the mass. Also present are 
numerous veinlets of cross-fiber asbestos which 
cut the dunite at various angles. 

On the east side, the dunite is in contact with 
hornblende gneiss that strikes about due north 
and dips 65° east. The contact on the west side 
of the dunite is covered by slump material but 
is also believed to be hornblende gneiss. Quartz- 
biotite gneiss is also present in the immediate 
area of the dunite, and a large concordant pegma- 
tite dike crops out in the south bank of the branch 
a few hundred feet south of the dunite body. 

Other prospects: Two peridotite bodies occur 
about 1.5 miles south of Spruce Pine just east of 
Grassy Creek. One body is located about 300 feet 
east of the bridge over Grassy Creek on the north 
side of Carters Ridge Road (SR 1117). A few 
outcrops are present in the road bank, but the 
main mass of the body lies north of the road and 
is present as disconnected boulder like outcrops 
that can be traced through the woods to near the 
crest of a prominent hill. 

The other peridotite body is located about 500 
feet south of SR 1117 directly behind a bowling 
alley that faces State Highway 26. An abandoned 



kaolin mine is located at the east end of this body. 
A road which leads to this mine cuts across the 
middle of the peridotite body. 

The composition of these two bodies show con- 
siderable variation. The bulk composition of the 
most southern body appears to be dunite although 
there is considerable alteration present along the 
southeast end of the body in the vicinity of kaolin 
mine. Selected samples collected from the body on 
the north side of SR 1117 are composed of inter- 
locking crystals of anthophyllite and tremolite. 
Microscopic examination revealed the bulk of the 
section to be composed of finely fibrous and acicu- 
lar anthophyllite and tremolite crystals arranged 
in an interlocking, subparallel schistose pattern. 
Remnants of massive olivine grains and fine gran- 
ules of magnetite are present throughout the 
section. Talc is concentrated in the finely fibrous 
anthophyllite. 

The high percentage of anthophyllite present 
in some of the outcrops present on the north side 
of SR 1117 indicate that this body may have po- 
tential as a mass-fiber deposit. However, the 
proximity of the deposit to the highway and 
several new homes may preclude any mining 
operations. 

Yancey County 

Blue Rock mine: The Blue Rock mine is located 
on the west side of the South Toe River about 2 
miles southeast of Micaville. It can be reached by 
travelling south on SR 1152, for 1.5 miles to the 
Blue Rock Church. Turn west onto a private farm 
road directly across from the church and follow 
this road for 0.5 mile to the river. A low water 
bridge makes the mine accessible by automobile 
or truck except during periods of high water. 

This mine has been worked intermittently since 
1941 by several different mining companies and 
has yielded a large tonnage of high grade, mass- 
fiber asbestos. It is presently being operated from 
time to time by the Blue Rock Mining Corpora- 
tion of Illinois. 

Most of the original rock mass has been re- 
moved by mining operations and only a small 
portion of the body remains in place. It is re- 
ported that prior to mining, the deposit was a 
large, massive outcrop that stood 25 to 30 feet 
above the surrounding ground level. Present 
workings show that the body is 100 feet long and 
40 wide at its maximum width. It is eliptical or 
pod shaped and its long dimension lies about N 
10° E. The dip of the northwest and southeast 



24 



contacts indicate that the body is oval shaped in 
vertical section and that it does not extend in 
depth more than about 20 feet below the present 
level of the quarry floor (subsequent exploratory 
drilling has confirmed that is the case). 

The ore body is located on the south slope of 
a steep hill and has been developed into the face 
of the hill. The present mine is an open pit quarry 
that is horseshoe shaped in outline with the south 
end open. The quarry walls are 20 to 30 feet high 
and consist of 5 to 10 feet of undisturbed ore rock. 
Waste material from the mine has been disposed 
of at the south end of the quarry and a large 
dump has been formed. 

One of the most interesting features of this 
deposit is the chlorite zone which completely en- 
velops the body, except at the south end where 
it has been removed by mining. The zone is from 
1 to 2.5 feet wide and is composed of extremely 
coarse-grained, emerald-green chlorite. It is par- 
ticularly well exposed along the north and north- 
west sides of the body. The outside of the zone is 
in sharp contact with a reddish-brown saprolite. 
The inside of the zone is in sharp contact with a 
zone of coarse-grained, nonfibrous anthophyllite 
rock which forms the walls of the quarry. In a 
few places the anthophyllite rock has separated 
from the chlorite zone along the contact and it 
is quite evident that there is no gradation be- 
tween the two rock types. Ore from the Blue Rock 
mine is of the mass-fiber variety and is character- 
ized by a radial, cone-like arrangement of the as- 
bestos fibers. It varies from light bluish grey to 
greenish gray in color and is composed mostly of 
anthophyllite and talc. 

In thin section the cone-like structures are re- 
vealed to be composed of finely acicular and fibr- 
ous anthophyllite and felted talc. Some of the 
acicular anthophyllite has been altered to talc, 
particularly along cross fractures and cleavage 
planes. However, the alteration to talc is more 
advanced in the finely fibrous anthophyllite. Skele- 
tal magnetite is sparcely scattered through the 
rock and usually has chlorite associated with it; 
however, chlorite most often occurs as isolated 
flakes. Anhedral magnesite occasionally occurs 
with the felted talc and finely fibrous anthophyl- 
lite. 

The average composition of two samples con- 
sidered to be typical ore is as follows : anthophyl- 
lite 65 percent; talc, 27 percent; olivine, trace; 
chlorite, 6 percent; serpentine, trace; magnesite, 
trace; others (mostly magnetite), 2 percent. 

The asbestos body is surrounded by a wide zone 



of reddish-brown saprolite which appears to be 
unusually high in iron. The saprolite zone grades 
into fine- to coarse-grained, quartz-muscovite 
schist that contains numerous stringers and pods 
of pegmatite. The schist strikes northeast and 
dips at a moderate to steep angle to the southeast 
and seems to be the predominant country rock, 
although interlayers of hornblende gneiss are also 
present. A large alaskite body corps out in the 
northwest bank of the river and extends to within 
120 feet of the south end of the asbestos body. 
Also, a large quartz vein is present 20 feet north 
of the asbestos body, and outcrops of another 
small ultramafic body are present 200 feet north- 
west. 

Newdale mine: The Newdale mine is located 0.5 
mile north of the South Toe River and U.S. High- 
way 19E, 1.1 miles northeast of Micaville. It can 
be reached by travelling on State Highway 80 for 
1 mile north of its intersection with U.S. Highway 
19E. At this point turn west onto SR 1304, and 
follow this road for about 1 mile to the mine. 

The Newdale mine is currently being developed 
by the Powhatan Mining Company and small 
amounts of mass-fiber ore have been produced in- 
termittently during the past 4 years. 

The ore body is a massive, oval shaped body of 
anthophyllite-enstatite rock that crops out on the 
crest of a long, narrow ridge. It is roughly circu- 
lar in outline and averages about 100 feet in 
diameter. The body forms a single, barren out- 
crop that stands up as much as 70 feet above the 
surrounding ground level. Most of the mining to 
date has been around the edges of the body, main- 
ly on the northeast and southwest sides. 

The ore rock is composed predominantly of 
large, interlocking crystals of enstatite that ex- 
hibit an advanced stage of alteration to antho- 
phyllite. The individual blade shaped crystals 
range from a fraction of inch up to 3 or more 
inches in length. On a fresh surface the rock is 
greenish gray to bluish gray in color and small 
talc flakes distributed throughout give it a silvery 
luster. 

In thin sections of the ore it is quite apparent 
that anthophyllite and talc have replaced much 
of the original enstatite. Some sections contain 
excellent examples of enstatite crystals that have 
been completely replaced by anthophyllite and 
talc. Enstatite occurs as large, highly altered 
blades. Finely fibrous bundles of anthophyllite are 
developed along cleavage cracks parallel to the 
long dimension of the enstatite. Acicular and 



25 



fibrous anthophyllite occurs interstitially as well 
as in random orientations that penetrate the 
blades in all directions. 

There is considerable variation in mineral com- 
position within the deposit. Anthophyllite, olivine 
and chlorite appear to be most abundant in the 
northern portion of the deposit whereas talc and 
enstatite are more abundant in the southern por- 
tion. 

An average mineral composition as determined 
from six thin sections representing both stockpile 
and in-place ore is as follows: anthophyllite, 45 
percent; enstatite, 15 percent; talc, 20 percent; 
olivine, 6 percent; chlorite, 7 percent; serpentine, 
5 percent; others (magnetite and chromite), 2 
percent. 

Where it has not been removed by mining 
operations, a narrow schistose zone of talc, chlor- 
ite and vermiculite is present between the antho- 
phyllite-enstatite rock and the country rock. The 
schistose zone varies from a few inches to several 
feet in width and an exposure in an open cut 
trench on the west side of the deposit exhibits 
numerous slickensides. The schistose zone is also 
well exposed in an abandoned adit that drifts part 
way under the deposit from the southeast side. 

The country rock that surrounds the ore body 
is a deeply weathered, coarse-grained quartz- 
muscovite schist that is thoroughly stained by 
iron oxide to a deep reddish-brown color. It con- 
tains numerous pods and stringers of pegmatite 
that are predominantly concordant to the local 
foliation, but a few are discordant. Adjacent to 
the ore body the foliation of the schist parallels 
the outline of the body ; however, away from the 
ore body the foliation of the schist strikes about N 
55° E and dips about 65° SE. Minor amounts of 
hornblende gneiss are interlayered with the schist. 
Numerous large pegmatites are in the general 
vicinity of the ore body. Extensive scrap mica 
workings are located about 700 feet southwest 
and several abandoned sheet mica mines are lo- 
cated within a few thousand feet north of the 
body. Also, a large dunite body is located about 
0.8 mile southeast of the asbestos mine between 
State Highway 80 and Mine Branch. 

J. C. Woody mine: The Woody mine is located 
on the southeast side of a northeast flowing tribu- 
tary to Rose Creek, about 0.5 mile south of Pleas- 
ant Grove Church. The mine can be reached by 
travelling on SR 1308 for 6.5 miles north of Mica- 
ville to Pleasant Grove Church. Turn southwest 
onto SR 1317 and travel about 0.75 mile to a farm 



read that turns south off of SR 1317 and leads 
to the Woody house. The mine is located 500 feet 
east of the house. 

This ultramafic body is composed mostly of rela- 
tively unaltered dunite. The body is about 500 
feet long, 200 feet wide and forms a prominent 
hill southeast of the creek. The asbestos ore is the 
peripheral zone mass-fiber variety and occurs in 
a zone about 2 feet wide that lies between the 
dunite and an alteration zone composed of talc, 
chlorite and vermiculite. 

The ore is massive, coarse grained and varies 
from cream to tan in color. It is composed of in- 
terlocking blades of asbestos fibers that contain 
small, isolated patches of fine grained, dark gray 
and black minerals. In thin section the ore is com- 
posed predominantly of acicular to finely fibrous 
anthophyllite. Concentrations of chlorite flakes in 
the anthophyllite produce the larger dark gray 
patches seen megascopically. A few small, dark 
gray to black patches are caused by clusters of 
magnetite granules. The anthophyllite fibers aver- 
age about 6 mm. in length, but fibers that range 
up to 12 mm. in length are not uncommon. Mineral 
composition of a selected sample of ore is as fol- 
lows: anthophyllite, 88 percent; chlorite, 10 per- 
cent; others (mostly magnetite and limonite), 2 
percent. 

The percent mine workings consist of a small 
open pit trench developed in the contact zone on 
the north side of body adjacent to the creek. The 
workings have not been extensively developed and 
because of the heavy growth of vegetation along 
the contact zone it is difficult to make a reliable 
estimate on tonnage of ore present. However, it 
appears that a fairly large tonnage of mass-fiber 
ore is present in this deposit. 

The predominant country rock is mica gneiss 
that strikes N 45° E and dips about 60° SE. At 
the southeast end, the body is in contact with a 
large pegmatite that has been mined for kaolin 
and mica. It is reported that several years ago a 
small amount of vermiculite was mined from the 
contact zone adjacent to the pegmatite. 

Sam Grindstaff mine: The Grindstaff mine is 
located en the northeast slope of Chestnut Moun- 
tain, 1000 feet southeast of Thunderstruck Knob. 
It can be reached by travelling on SR 1308 for 
5.6 miles north of Micaville to SR 1312. Turn 
west on to SR 1312 and travel 0.2 mile to the in- 
tersection with SR 1319. Turn northwest onto SR 
1319 and followed this road 0.4 mile to its termi- 
nation. The mine is located about 1000 feet north- 



26 



west of the end of SR 1319 and can be reached on 
foot by following an abandoned logging road. 

This ultramafic body is predominantly dunite 
and is about 300 feet long and 150 feet wide. It 
underlies the south slope of a prominent hill and 
forms numerous boulder-like dun colored out- 
crops. The mine workings are located at the north 
end of the deposit and consist of a shallow open 
cut trench that is up to 10 feet wide and about 75 
feet long. The long dimension of the trench lies 
in a northeast-southwest direction and dips at a 
moderate angle to the northwest. Several smaller 
prospect pits and trenches are located in the 
immediate vicinity. The main trench appears to 
be located along an interior fault or shear plane. 

The asbestos occurs as a series of cross-fiber 
veins that range from Y> inch to 5 inches in width. 
It appears to be relatively free of impurities and 
of good quality; however, the quantity of ore is 
limited. An unknown amount of asbestos was re- 
covered from this mine a number of years ago, 
but it has not been worked for at least the past 
ten years. 

An exposure on the northwest side of the body 
reveals that the dunite is in direct contact with 
hornblende gneiss that strikes N 60° W and dips 
80° NE. The usual talc-chlorite-vermiculite alter- 
ation zone is absent at the contact, but a small 
pegmatite stringer that is offset about 1 foot indi- 
cates some faulting along the contact. 

Cas Thomas prospect: A small body of enstato- 
lite occurs on the Cas Thomas farm about 5.5 
miles airline north of Micaville. The deposit can 
be reached by travelling on SR 1308 for 7.6 miles 
north of Micaville to SR 1315. Turn northeast 
onto SR 1315 and follow this road for 1.2 miles 
to the Thomas farm. The deposit is located about 
1000 feet southeast of the Thomas house near the 
North Toe River. 

The deposit consists of a few boulder like out- 
crops of enstatolite that occur near a small tribu- 
tary stream. The area is covered with a thick 
mantle of soil and heavy growth of vegetation and 
the true dimensions of the body could not be 
determined. However, it appears that the deposit 
is less than 100 feet long. The deposit was pros- 
pected for asbestos some years ago, but no ore 
was produced. However, the deposit may have 
potential as a source of mass-fiber asbestos of 
the anthophyllite-enstatite variety. 

C. W. Allen prospect: An abandoned asbestos 
mine is located on the C. W. Allen property, 4.5 
miles airline southwest of Burnsville. The de- 



posit can be reached by travelling on U.S. High- 
way 19 E for 5.6 miles west of Burnsville to the 
intersection with SR 1136. Turn south onto SR 
1136 (Banks Creek Road) and follow this road 
for 1.7 miles. Outcrops of dunite are exposed in a 
roadcut on the south side of the road 150 feet 
southwest of Allen Cemetery. 

Relatively unaltered, dark-gray to green dunite 
is exposed for about 80 feet along the roadcut. It 
is in contact with hornblende gneiss on the south- 
east side and quartz-muscovite gneiss on the 
northwest side. The gneisses strike N 15 °E and 
have a moderate dip to the southeast. The dunite 
body can be traced southwest across an open pas- 
ture for about 500 feet where it is well exposed 
in the abandoned asbestos workings. In the im- 
mediate vicinity of the mine area the dunite ex- 
hibits various degrees of alteration. Some hand 
specimens collected from the dump show relict 
grains of olivine that are completely altered to 
serpentine. 

Very little asbestos can be seen in place, but 
pieces picked from the mine dump indicate that 
the asbestos ore was the cross-fiber vein variety. 
Veins up to 3 inches in width are present and the 
asbestos is stained a light yellowish brown by iron 
oxide. The only impurities noted were a few flakes 
of chlorite in the outer portion of the vein. 

The mine is evidently the one referred to as the 
Cane River mine that was worked in 1919 by 
Mr. N. C. McFalls. No production records are 
available, but from the size of mine workings, it 
appears that only a few tons of asbestos were 
recovered. 

Other prospects: There are a number of other 
ultramafic bodies scattered throughout Yancey 
County. Time did not permit the exact location 
and examination of many of these deposits and 
their potential as asbestos prospects is unknown. 
The general location of some of these deposits are 
shown on the accompanying maps. 

LAKE TOXAWAY AREA 

Beginning in southern Jackson County near the 
South Carolina state line, and continuing north- 
east into western Transylvania County, an area 
approximately 15 miles long and 5 miles wide con- 
tains between 30 and 40 bodies of ultramafic 
rocks. Lake Toxaway is about the geographic cen- 
ter of this area. 

All of the ultramafic bodies in this area are 
small and are characterized by an advanced stage 



27 



Figure 4 




0.5 



Scale 





1 Mile 




Micaville 

7.5 Minute-Quad 



N 



I 



MAP SHOWING LOCATION OF ASBESTOS MINES IN 
THE BRUSH CREEK AREA, YANCEY CO., N. C. 



28 



Figure 4. Map showing location of asbestos mines in the 
Brush Creek area, Yancey County, North Carolina. 



of alteration. Large tonnages of mass-fiber asbes- 
tos of the peripheral zone type have been mined 
from some of the deposits and the area also con- 
tains large reserves of mass-fiber asbestos of the 
anthophyllite-enstatite variety. 

Transylvania County 

Kilpatrick mine: The Kilpatrick mine is located 
about 5.8 miles airline northwest of Rosman and 
3 miles airline northeast of the post office at 
Lake Toxaway. It can be reached by travelling on 
State Highway 281 for 5.2 miles north of its inter- 
section with U.S. 64 to SR 1309. Turn east onto 
SR 1309 and travel 1.2 miles to a farm road on 
the north side of SR 1309. The mine is located at 
the end of this road about 500 feet north of the 
farm house. 

This mine was worked intermittently for several 
years by the Powhatan Mining Company and 
yielded a large tonnage of high grade anthophyl- 
lite asbestos. It was abandoned in 1962 and the 
mine workings have been back filled and leveled. 

The ultramafic body at this locality appears to 
be a dunite that has undergone considerable al- 
teration. Outcrops of the main mass are poor and 
those present are deeply weathered to an orange- 
brown clay that contains numerous small flakes 
of talc and asbestos fibers. The body lies on the 
slope of a small hill and is covered with soil and 
dump material from the mine and the exact 
dimensions of the body could not be determined. 
However, it appears to be between 200 and 300 
feet long and about 100 feet wide. Outcrops of 
ultramafic rocks of about the same composition 
occur 500 feet southeast and may be part of the 
same body or represent another separate mass. 

The mine was developed in the peripheral zone 
along the west side at the north end of the body. 
The workings consisted of an open cut trench 100 
feet long, 20 feet wide and 15 to 20 feet deep, that 
dipped about 45 degrees to the west. The hanging 
wall of the cut was developed in the country rock 
which consisted predominantly of layered, fine- 
grained, quartz-feldspar-muscovite gneiss. How- 
ever, adjacent to the contact, pegmatite contain- 
ing irregular shaped xenolites of hornblende 
gneiss predominated. The footwall consisted of 
the peripheral zone of anthophyllite asbestos and 
the deeply weathered ultramafic rock. The con- 
tact between the pegmatite and anthophyllite 
zone was very sharp and regular. The contact be- 
tween the anthophyllite zone and the main mass 



of the ultramafic body was also sharp but some- 
what irregular. 

The anthophyllite zone varied from 3 to 6 feet 
in width and consisted of soft, buff to tan colored, 
coarse-grained mass-fibered asbestos. Most of the 
zone was ore grade material and the only visible 
impurities were talc and dissiminated flakes of 
chlorite. 

At the time the mine was abandoned consider- 
able ore remained in place. However, owing to the 
dip of the peripheral zone the ore could no longer 
be removed economically by open cut methods. 

Oakland mine: This deposit is located about 
400 feet southwest of U.S. Highway 64 next to a 
small draw that leads to a southwest flowing 
tributary to Horsepasture River. It can be 
reached by following an abandoned logging road 
that leaves U.S. Highway 64, 0.35 mile northwest 
of the intersection of SR 1152 (Sapphire Road) 
with U.S. Highway 64. SR 1152 is located a few 
hundred feet northwest of the small community 
of Oakland. The logging road is also located 1.45 
miles east of the Jackson-Transylvania county 
line. 

The deposit consists of several large outcrops 
of highly altered and weathered enstatolite. The 
outcrops are present for about 75 feet along 
strike (notheast-southwest) and are about 30 
feet wide. The rock is massive, dark gray to 
greenish gray in color and is composed of large, 
interlocking blades of enstatite that are highly 
altered to anthophyllite and talc. In thin section, 
randomly oriented blades of enstatite are inter- 
locked with finely fibrous anthophyllite and bladed 
and acicular tremolite. The enstatite blades ap- 
pear as large poikilitic areas that include ran- 
domly oriented flakes of talc and chlorite, as well 
as fibrous and acicular crystals of actinolite. 
Bundles of anthophyllite fibers most often occur 
along cleavage planes and are oriented parallel to 
the vertical axis of the enstatite crystals. The 
mineral composition of the rock is as follows: 
anthophyllite, 34 percent; enstatite, 24 percent; 
tremolite 23 percent; talc, 13 percent; olivine, 3 
percent; chlorite, 2 percent; others, 1 percent. 

The asbestos workings consist of a cut that 
circumvents the body and two cuts that cut across 
it. The cut around the body was evidently devel- 
oped in the peripheral zone of alteration. How- 
ever, the mining operations have disturbed the 
surrounding area to the extent that very little 
material is in place and no definite relationships 



29 



could be established. Contacts with the country 
rock were not exposed, but at one place along 
the southwest side of the body a small area was 
covered with muscovite mica and what appeared 
to be hornblende gneiss. 

This deposit was prospected by the Powhatan 
Mining Company and evidently only a small 
amount of mass-fiber ore was recovered. 

Walnut Cove Creek mine: This deposit is lo- 
cated about 1.5 miles south of the Kilpatrick mine 
on the west side of Walnut Cove Creek. It can be 
reached by travelling on State Highway 281 for 
3.7 miles north of its intersection with U.S. High- 
way 64. At this point an abandoned farm road 
turns southeast off of State Highway 281. The 
deposit is located at the end of this farm road 
about 0.75 mile east of State Highway 281. 

This deposit is a narrow, lense shaped mass of 
highly altered and deeply weathered peridotite. 
It is about 250 feet long (N 10° E), 50 feet wide 
and appears to be dipping steeply to the north- 
west. The contact zone is well exposed along the 
west side for practically the entire length of the 
body. It displays a narrow contorted and schistose 
zone of talc, chlorite and vermiculite that sepa- 
rates the altered peridotite from the country rock. 
The country rock is composed mostly of medium 
to fine-grained, quartz-biotite gneiss that con- 
tains numerous stringers and pods of pegmatite. 
Near the contact zone the gneiss is strongly 
folded. 

The asbestos workings consist of an open cut 
trench developed parallel to the west side of the 
body for its entire length. The trench was cut 
parallel to the peripheral zone, but it has been 
backfilled and no ore could be seen in place. 

This deposit was worked by the Powhatan Min- 
ing Company and an unknown amount of mass- 
fiber asbestos of the peripheral zone type was re- 
covered. The mine has been abandoned for about 
10 years. 

Miller mine: The Miller mine is located on the 
south slope of Rainy Knobs Mountain about 1 mile 
south of Sapphire. It can be reached by travelling 
on U.S. Highway 64 for 3.1 miles west of Toxa- 
way Falls to SR 1152. Turn southwest onto SR 
1152 and travel 3.75 miles to Windy Gap. At this 
point a logging road turns southeast off of SR 
1152. Follow this logging road for about 0.25 mile 
to the first bifurcation. The deposit can be reached 
on foot from this point by following the left fork 
for about 1000 feet. 



This deposit consists of a more or less con- 
tinuous massive outcrop of enstatolite. It occurs 
as a lense shaped body about 170 feet long with 
the long dimension alined almost due north-south. 
The north end of the body is about 90 feet wide 
and the south end is 60 feet wide. The body stands 
up from 5 to 20 feet above the surrounding 
ground level. 

The predominant rock type at this deposit is a 
highly altered enstatolite composed of large, in- 
terlocking, lath-shaped crystals of enstatite and 
anthophyllite. The enstatite crystals are gray to 
greenish gray in color and average V2 inch in 
width and 1 inch in length. Anthophyllite occurs 
as long, slender bundles of fibers that are oriented 
parallel to the long direction of the enstatite 
crystals. Talc gives much of the rock a silvery 
luster and chlorite occurs as small, dark-green 
sheets that are scattered throughout the ground- 
mass. Dark gray to green olivine grains are notic- 
able in many hand specimens and seem to be more 
abundant in the northern half of the deposit. 

Where it has not been removed or covered by 
mining operations, a narrow zone of schistose talc, 
chlorite and vermiculite completely surrounds the 
enstatolite body. This zone is particularly well 
exposed along the northeast side of the body. 

A thick mantle of soil and heavy growth of 
vegetation mask the area around the deposit and 
no outcrops of country rock were observed. How- 
ever, 200 feet east of the deposit several good 
exposures of country rock are present along the 
road that leads to the mine. The predominant 
rock type is a coarse-grained, quartz-feldspar- 
mica gneiss that strikes north and dips at a 
moderate angle to the west. A concordant pegma- 
tite is exposed for about 20 feet along the road 
and further east interlayers of hornblende gneiss 
are present. 

In thin section enstatite appears as large, 
colorless, interlocking laths that are irregular in 
outline. The prominent cleavage is parallel to the 
long direction of the blades. Cross sections of 
enstatite crystals display typical pyroxene cleav- 
age. Other mineral components occur as inclusions 
in the enstatite or are interstitial to it. Antho- 
phyllite occurs mainly as long asbestiform fibers 
along cleavage cracks parallel to the enstatite. 
Under plain light anthophyllite could be mistaken 
for a fibrous form of enstatite. However, under 
crossed nicols the second order interference colors 
of anthophyllite clearly distinguish it from the 
low first order colors of enstatite. Parallel extinc- 



30 



tion distinguishes anthophyllite from the mono- 
clinic amphiboles tremolite, actinolite and cum- 
mingtonite. Long, slender anthophyllite needles 
and fibers also occur in interstices and in random 
orientations that penetrate the other minerals 
without regard to grain boundaries. 

Talc is present primarily as an interstitial al- 
teration product developed between the enstatite 
blades and frequently forms embayments in the 
enstatite. It also occurs as an alteration product 
of anthophyllite and enstatite, particularly along 
parting and cleavage planes. Irregularly frac- 
tured skeletal remnants of fresh olivine are 
sparsely distributed throughout the section. 
Flakes of chlorite occur most often as alteration 
products in the enstatite. The contact between the 
chlorite and enstatite is usually marked by a thin 
layer of very fine-grained talc. 

Small, opaque skeletal fragments of magnetite 
are disseminated throughout the section studied 
and are particularly concentrated in the chlorite 
and talc. Chromite occurs as irregular, somewhat 
rounded grains sparsely distributed through the 
enstatite. Unlike the completely opaque magnetite, 
the chromite is slightly translucent in very thin 
areas and transmits a dark coffee brown light. 

The mineral composition of a typical specimen 
of enstatolite found at the Miller mine is as fol- 
lows: anthophyllite, 15 percent; enstatite 64 per- 
cent ; talc, 12 percent ; olivine, traces ; chlorite, 6 
percent; serpentine, trace; others (magnetite, 
chromite and pyrite), 2 percent. 

Numerous cross-fiber anthophyllite veins cut 
the enstatolite body in all directions. The veins 
are white to buff colored and range from less than 
1 inch up to 5 inches in width. A thin section of 
one of these veins cut perpendicular to the vein 
walls reveals that the center portion of the vein 
material is composed almost entirely of fibrous 
anthophyllite. The fibers are oriented perpendi- 
cular to the vein walls and are stained by minor 
but widespread reddish-brown iron oxide. Chlorite 
flakes are intermingled with the anthophyllite 
near the edges of the vein and become predomi- 
nant along the margins of the vein. The mineral 
composition of the cross-fiber vein is as follows : 
anthophyllite, 77 percent; chlorite, 16 percent; 
serpentine, 3 percent; talc, 1 percent; others, 3 
percent. 

This deposit was prospected by the Powhatan 
Mining Company and a small tonnage of mass- 
fiber ore of the anthophyllite-enstatite variety 
was mined about 8 years ago. The mine has been 



inactive since that time. The mine workings con- 
sist of a vertical face developed along the south 
and southeast sides of the body. It has a maximum 
height of 18 feet on the south side and gradually 
descends to a height of 8 feet at the northeast end. 
The total length of the face is 120 feet. Prospect 
trenches from 40 to 60 feet in length were cut 
into the body from the southwest, west and north 
sides. 

Contact relationships suggest that only the 
upper part of this body is exposed above the pres- 
ent ground level. If this is the case, then consider- 
able ore remains in place. 

Jennings No. 1 mine. This deposit is located on 
the northeast side of Whitewater River, 5.0 miles, 
airline, southeast of Cashiers. It can be reached 
by travelling on State Highway 107 for 5.9 miles 
southeast of its intersection with U.S. Highway 
64 to SR 1103. Turn southeast and travel 0.6 
mile to where SR 1103 ends. At this point an 
abandoned logging road leads northeast to the 
river, a distance of about 0.5 mile. The mine is 
located 100 feet northeast of the river and can be 
reached only on foot. 

This deposit consists of a single massive out- 
crop of highly altered peridotite. It is about 50 
feet long, 20 feet wide and lies in an eastwest direc- 
tion. The attitude of the contact zone on the north 
side of the body suggests that only the upper part 
of the body is exposed, and it may be considerably 
larger than the present outcrop indicates. 

The deposit was prospected by the Powhatan 
Mining Company about 1957 and a small tonnage 
of mass-fiber asbestos of the peripheral zone va- 
riety was recovered. The mine workings consist 
of an open cut trench 100 feet long and 75 feet 
wide developed in an east-west direction along 
the north side of the body. The cut was developed 
parallel to the contact zone and exposes it for most 
of the length of the cut. The contact zone is ex- 
tremely complicated and varies rapidly along 
strike. In general, it is composed of a layer of 
mass-fiber asbestos that in places is up to 3 feet 
thick. The asbestos zone is bounded on one side 
by peridotite and on the other by a thin zone of 
schistose chlorite and vermiculite. 

No outcrops of country rock are exposed in the 
area adjacent to the mine and the relationship of 
the peridotite to the surrounding rock could not 
be established. However, a small pegmatite dike 
is exposed in the north face of the cut and small 
masses of badly fracture tourmaline crystals and 



31 



numerous small garnets were noted in the dump 
material. 

Socrates prospect: This deposit is located 0.75 
mile, airline, southwest of Sapphire and about 
1000 feet west of SR 1152. It can be reached by 
travelling on SR 1152 for 0.7 mile southwest of 
Sapphire and the intersection with SR 1153. At 
this point an abandoned logging road turns west 
off of SR 1152. The deposit can be reached by fol- 
lowing this logging road on foot for about 1000 
feet. 

This is the site of the Socrates corundum mine 
which was worked by the Sapphire Corundum 
Company during the 1890's (Pratt and Lewis, 
1905, p. 44). The corundum workings are quite 
extensive and consist of a number of open cut 
trenches developed across and parallel to the con- 
tact zone. Most of the work appears to have been 
done on the north side of the body. 

Although the exact dimensions of this deposit 
are unknown it is at least 200 feet wide and 700 
feet long. It occurs on the slope above a northeast 
flowing tributary to Horsepasture River and 
forms many massive ledges and boulder-like out- 
crops that stand up as much as 40 or 50 feet 
above the creek. The bulk composition of the de- 
posit is apparently dunite or peridotite that has 
undergone considerable alteration. 

Two types of mass-fiber anthophyllite asbestos 
occur in this deposit. One is typical mass-fiber 
asbestos of the peripheral zone type and the other 
is a somewhat unusual rock composed mostly of 
anthophyllite and olivine. The anthophyllite- 
olivine rock occurs in the central area of the 
deposit and appears to form a large part of the 
body. It is massive, greenish to brownish gray in 
color and very coarse grained. Fibrous antho- 
phyllite is the predominant constituent and occurs 
as randomly oriented, interlocking blades that 
are commonly 3 to 4 inches in length. 

In thin section the rock is revealed to be com- 
posed predominantly of finely fibrous, acicular, 
primatic anthophyllite and olivine along with 
minor amounts of colorless, acicular tremolite. 
The anthophyllite and tremolite are randomly 
oriented in an interlocking texture and regularly 
penetrate remnants of olivine grains. Simultane- 
ous extinction of the remnants of one large olivine 
grain indicates a maximum grain diameter of 12 
mm. Average fiber length of the anthophyllite is 
about 4 mm, but fibers in some of the large antho- 
phyllite blades may be as much as 2 or 3 inches 
long. Chlorite and magnetite are randomly dis- 



tributed throughout the section both poikilitically 
and interstitial to the anthophyllite, tremolite and 
olivine. Talc occurs most commonly as flakes and 
small irregular patches in the fibrous anthophyl- 
lite. 

The mineral composition of the anthophyllite- 
olivine rock is as follows: anthophyllite, 55 per- 
cent; olivine 22 percent; tremolite, 6 percent; 
chlorite, 6 percent; talc, 5 percent; magnesite, 1 
percent; serpentine, trace; others (magnetite, 
chromite and limonite), 5 percent. 

This deposit has not been prospected for asbes- 
tos, but it appears to have considerable potential. 

Other prospects: In addition to the above men- 
tioned mines and prospects there are a number of 
other ultramafic bodies in Transylvania County, 
a few of which have been prospected for asbestos. 
Two of these are located along SR 1322, 0.50 mile 
and 0.80 mile respectively east of its intersection 
with SR 1309. A small body of enstatolite is lo- 
cated on the Fisher property on the north slope 
of Little Panthertail Mountain 1.75 miles, airline, 
northwest of the intersection of SR 1306 and 
State Highway 281. Another small prospect is 
located on the southwest side of Toxaway Lake 
1.3 miles, airline, northwest of the intersection 
of State Highway 281 and U.S. Highway 64. An 
ultramafic body 100 feet long and 75 feet wide 
occurs on the east slope of Toxaway Mountain 
700 feet SSE of the waterfalls on Mill Creek. The 
deposit is highly altered and composed mostly of 
anthophyllite, actinolite and chlorite. Numerous 
corundum prospect pits are in and around the 
edges of the body. 

Small amounts of slip-fiber asbestos are present 
in the dumps of several prospect pits on the L. E. 
Cash property. The prospects pits are located 700 
feet north of the Bohaynee Road (SR 1149), 1.1 
miles southwest of where the road crosses Horse- 
pasture River. 

Jackson County 

Asbestos mine: This deposit is located on the 
east side of U.S. Highway 64, 1.0 mile west of the 
Jackson-Transylvania county line. The mine is 
within 150 feet of the highway and is directly 
across from the entrance to the service road to the 
Fire Tower on Toxaway Mountain. 

The body is exposed over an area 150 feet in 
length and 50 feet in width, but waste material 
from the mine workings covers much of the area 
around the body and the exact dimensions could 



32 



Figure 5 




Scale 



05 



2 Miles 




MAP SHOWING LOCATION OF ASBESTOS MINES 
IN THE SAPPHIRE VALLEY AREA,NC 



Figure 5. Map showing location of asbestos mines in the Sap- 
phire Valley area, North Carolina. 



33 



not be established. Most of the body consists of 
dark gray to greenish gray, fine-grained dunite 
that locally contains significant amounts of antho- 
phyllite. 

A thin section of a specimen considered to be 
representative of the bulk of the deposit revealed 
the rock to be composed mostly of somewhat 
spherical olivine grains that are moderately to 
highly fractured. Simultaneous extinction of sev- 
eral fragments indicates an original average grain 
size of about 0.5 mm. Anthophyllite occurs -as 
fibrous and acicular crystals that average about 
3 mm. in length and penetrate the olivine grains 
in all directions. Subhedral to euhedral chromite 
grains are sparsely distributed throughout the 
section and clusters of fine, opaque granules of 
magnetite occur around the boundaries of the 
olivine grains. Randomly oriented flakes of talc 
and chlorite are very sparsely distributed 
throughout the section. Talc is slightly more abun- 
dant than chlorite and is most often associated 
with finely fibrous anthophyllite. The mineral 
composition of the dunite is as follows: olivine, 
73 percent; anthophyllite, 22 percent; talc, 3 per- 
cent; chlorite, 1 percent; others (chromite and 
magnetite), 1 percent. 

Anthophyllite also occurs as narrow cross-fiber 
veins that cut the body in all directions and in 
the peripheral zone of alteration. 

This deposit was worked intermittently by the 
Powhatan Mining Company during the period 
1958-1962, and a large tonnage of high grade, 
mass-fiber asbestos of the peripheral zone type 
was recovered. The mine workings consisted of 
an open cut trench developed parallel to the con- 
tact zone along the east and northeast sides of 
the body. The cut was about 100 feet long, 20 to 
30 feet wide and up to 20 feet deep at the north- 
east end. It has been backfilled and leveled over. 

The asbestos zone was quite irregular and 
varied from a few feet up to 10 feet in width. 
Most of the variation in width took place along 
the contact between the asbestos zone and the 
dunite. The outside contact of the asbestos zone 
was marked by a narrow, but regular zone of 
schistose talc, chlorite and vermiculite. A narrow 
quartz vein paralled the contact zone for about 
20 feet along the northeast side of the cut. 

The asbestos ore consisted mostly of flat, inter- 
locking bundles of fibers that ranged from less 
than 1 inch to over 4 inches in length. Most of the 
ore had a light buff to tan color, but individual 
fibers were white when separated from the mass. 



Small flakes of chlorite and talc developed parallel 
to the length of the fibers were the only impurities 
noted. 

Three other ultramafic bodies which were pros- 
pected for asbestos by the Powhatan Mining Com- 
pany are in close proximity of the Asbestos mine. 
One of these is located directly across the high- 
way from the Asbestos mine. It is of the same 
composition, but appears to be a separate body. 
A relative large dunite-enstatolite body is located 
on the west side of Hogback Creek and the south 
side of U.S. Highway 64, 0.6 mile east of the 
Asbestos mine. This deposit was prospected dur- 
ing 1961 and a small amount of mass-fiber ore of 
the anthophyllite-enstatite variety was recovered. 
The third deposit is located on the northeast side 
of U.S. Highway 64, 0.80 mile east of the Asbestos 
mine and 0.4 mile west of the Jackson-Transyl- 
vania county line. 

Rattlesnake prospect: The Rattlesnake prospect 
is located on the south slope of Hogback Mountain. 
0.5 mile northeast of the Asbestos mine. The de- 
posit can be reached by travelling on the Fire 
Tower service road (this is a private road and 
entrance is by permit only) for 0.7 mile north of 
its intersection with U.S. Highway 64. At this 
point a foot trail is present on the east side of 
the road. The deposit can be reached by following 
this trail along the contour of the mountain side 
for about 2000 feet. 

This is the site of the Rattlesnake corundum 
mine which was worked by the Sapphire Corun- 
dum Company during the 1890's. The deposit has 
not yet been worked for asbestos, but it is of 
interest because bulk samples of mass-fiber ore 
were collected here for mineral dressing studies. 

The body crops out on the crest of a north-south 
trending ridge and forms a lens shaped mass that 
is about 100 feet wide and 300 feet long with the 
long axis alined north and south. The exact dimen- 
sions are difficult to determine because of soil and 
vegetation cover and the deposit may be larger 
than indicated. 

The rock is unusually coarse textured through- 
out the deposit and consists mainly of large ra- 
diating blades of enstatite that are partially al- 
tered to anthophyllite and grains of olivine that 
are occasionally an inch or more in diameter. 
Cross-fiber veins of anthophyllite that range from 
14 inch up to 5 inches in width cut the body in all 
directions and are particularly numerous in the 
north end of the deposit. 



34 



In thin section the enstatite and olivine are ar- 
ranged in an interlocking texture of randomly 
oriented enstatite blades and massive olivine 
grains. Prismatic sections of enstatite appear as 
elongated laths or blades with cleavage parallel to 
length. Basal sections of enstatite display typical 
pyroxene cleavage. Olivine occurs as large, ir- 
regularly shaped grains that are highly fractured. 
Grains up to 1.5 inches in diameter are not un- 
common, but most average about 0.25 inches in 
diameter. Anthophyllite occurs primarily as 
fibrous bundles developed along cleavage cracks 
parallel to the length of the enstatite blades. It 
also occurs interstitialy, and as randomly oriented 
crystals that penetrate the other minerals in all 
directions. The anthophyllite displays a wide 
range in fiber length, but averages about 3 mm. 

Talc and chlorite are the main accessory min- 
erals. Chlorite occurs mostly as an alteration 
product associated with enstatite and olivine, 
whereas talc is most often associated with ensta- 
tite and anthophyllite. Small irregular shaped 
grains of magnetite are distributed throughout, 
but are particularly concentrated in the chlorite. 
Yellowish-green serpentine is sometimes present 
in the fractures of the enstatite blades. The aver- 
age mineral composition of two sections of this 
rock is as follows: enstatite, 38 percent; olivine, 
30 percent; anthophyllite, 13 percent; talc, 13 per- 
cent, chlorite, 4 percent; serpentine, 1 percent; 
others (mostly magnetite), 1 percent. 

Extensive corundum workings that were de- 
veloped parallel to the contact zone are present 
along the east side of the body. The cuts are now 
badly slumped and overgrown with vegetation and 
reveal very little about the nature of the contact 
zone or the relationship with adjacent country 
rock. However, observations made at several 
places around the edges of the deposit indicate 
that the peripheral zone may contain considerable 
quantities of mass-fiber asbestos. 

Brockton mine: This deposit is located about 
0.3 mile northeast of the Rattlesnake mine on the 
west side of a deep ravine formed by Hogback 
Creek. Access to the mine is by way of an aban- 
doned logging road that intersects U.S. Highway 
64 a few hundred feet west of the Jackson-Tran- 
sylvania county line. The mine is located about 
0.8 mile north of the highway. 

This deposit was also worked by the Sapphire 
Corundum Company and according to Pratt and 
Lewis (1905, p. 256), " about 72 



tons of a dull gray crystal and sand corundum 
were obtained from two shallow pockets that were 
entirely within the peridotite formation, but near 
its contact with the gneiss". Some of the corun- 
dum workings are still preserved and consist of a 
vertical shaft at the north end of the body and 
an adit of unknown length that appears to drift 
under the deposit along the contact zone from 
the southwest side. 

The main body covers an outcrop area of about 
100 feet by 250 feet in which the long dimension 
is alined northeast. However, several large, iso- 
lated outcrops of similar ultramafic rocks are 
present a few hundred feet north and northwest 
and may represent part of the same body or a 
separate smaller mass. 

Texture of the rock at this deposit is quite 
similar to that at the Rattlesnake mine in that it 
is uniformly coarse grained. It is also composed 
predominantly of large radiating and interlocking 
enstatite crystals. However, it contains consider- 
ably more anthophyllite and is lacking the coarse 
olivine grains present in the Rattlesnake deposit. 
The mineral composition of a typical specimen of 
this rock is as follows : anthophyllite 58 percent, 
enstatite, 35 percent ; magnesite, 1 percent ; others 
(mostly magnetite), trace. 

The Powhatan Mining Company prospected 
this deposit during the spring of 1962 and mined 
a small tonnage of mass-fiber ore of the antho- 
phyllite-enstatite variety. 

Bad Creek prospect: This deposit is located 0.3 
mile southwest of the Socrates mine (Transyl- 
vania County) near the headwaters of a north- 
west flowing tributary to Horsepasture River. It 
is situated in a very inaccessible area and can be 
reached only on foot. 

The body forms a lenticular mass about 50 feet 
wide and 200 feet long with the long dimension 
alined northwest. Extensive corundum workings 
developed parallel to the contact zone are present 
along the northeast side of the body. The work- 
ings consist of an open cut trench over 100 feet 
long, 15 to 20 feet wide and up to 30 feet deep in 
places. The contact zone is well exposed in several 
places along the cut and is composed mostly of 
schistose chlorite and vermiculite. Hornblende 
gneiss and schist is in contact with the chlorite - 
vermiculite zone but the predominant rock type 
around the body is quartz-biotite-muscovite 
gneiss. 

The southeast end of the deposit is highly al- 



35 



tered, very coarse grained and contains a high 
percent of fibrous anthophyllite. The northwest 
end is less altered, finer grained and contains con- 
spicuous amounts of olivine. A thin section of a 
specimen considered to be typical of the deposit 
at the northwest end had the following mineral 
composition: anthophyllite, 58 percent; tremolite. 
24 percent; olivine, 12 percent; chlorite, 3 per- 
cent; talc, 2 percent; others (limonite, magnetite, 
magnesite), 1 percent. The mineral composition 
of a specimen typical of the southeast end is as 
follows: anthophyllite, 70 percent; tremolite, 19 
percent; olivine, trace; talc, 6 percent; chlorite, 
4 percent; others (limonite, magnetite, magne- 
site), 1 percent. 

This deposit has not been worked for asbestos, 
but it appears to have considerable potential as a 
source for mass-fiber asbestos. 

Jennings No. 2 mine: This deposit is located on 
the west side of Whitewater River, about 1000 
feet southwest of Jennings No. 1 mine. Access is 
by the same route that leads to the Jennings No. 
1 mine. 

The body occurs on the crest of a short spur 
ridge and forms several large, massive outcrops 
that stand up as much as 20 to 25 feet above the 
surrounding ground level. Outcrops indicate that 
the deposit is about 220 feet long and 115 feet 
wide with the long dimension alined east and 
west. The body is composed chiefly of large radiat- 
ing and interlocking blades of grayish-green 
enstatite and olivine. A narrow outcrop of quartz- 
muscovite schist is present at the southeast end 
of the body. It contains thin layers of pegmatite 
and strikes N 45° E and dips 70° SE. 

The, deposit was prospected by the Powhatan 
Mining Company about 1950 by means of open 
cut trenches developed parallel to the contact zone 
along the north and south sides of the body. Small 
cross-cutting trenches are present at the east and 
west ends of the deposit. A small amount of 
cross-and mass-fiber ore was evidently recovered 
but the deposit was not extensively developed. 

This is also the site of the Whitewater Corun- 
dum mine and the entrance to an adit, which was 
the main mine workings, is located at the west 
end of the deposit. 

Round Mountain mine: This deposit is located 
on the northeast side of Round Mountain, 7.0 
miles, airline, southeast of Cashiers and 1.0 mile 
southwest of Upper Falls on Whitewater River. 
Access is by means of a National Forest service 



road that intersects State Highway 107 at Heady 
Mountain Gap, 6.0 miles south of U.S. Highway 
64. 

This deposit was worked by the Powhatan Min- 
ing Company about 1956 and 1957 and a relatively 
large tonnage of high grade, mass-fiber asbestos 
was recovered. The ore was recovered from an 
open cut about 200 feet long, 175 to 200 feet wide 
and 70 feet deep. The long dimension of the cut is 
northeast-southwest. A deep drainage ditch was 
cut at the northeast end and connects with a small 
stream. Most of the waste material from the mine 
was dumped on the southeast side of the drainage 
ditch. 

During the process of mining the entire perido- 
tite body was removed and country rock is 
exposed on three sides of the cut. It is a coarse- 
grained quartz-biotite gneiss that contains num- 
erous layers and stringers of pegmatite. It strikes 
N 15° E and dips 70° NW and the peridotite body 
was evidently conformable to the foliation of 
gneiss. 

As the deposit was completely mined out the 
composition of this ultramafic body and the rela- 
tionship of the asbestos to it is unknown. How- 
ever, a few loose blocks on the dump indicate that 
the body was in part altered dunite that contained 
numerous cross fiber veins of asbestos. Some of 
the asbestos ore was the cross-fiber vein variety, 
but the majority of it was most likely the mass- 
fiber variety. 

Coldsides Mountain mine: This deposit is lo- 
cated on the south side of Coldsides Mountain, 
5.5 miles airline south of Cashiers and 2.0 miles 
northwest of where State Highway 107 crosses 
into South Carolina. The mine can be reached by 
travelling on State Highway 107 for 6.95 miles 
south of its intersection with U.S. Highway 64 
at Cashiers. Turn west onto SR 1100 (Bull Pen 
Road) and travel 1.45 miles to a logging road on 
the north side of SR 1100. Follow the logging 
road for 0.2 mile to where it crosses Licklog 
Creek. From this point walk in a west to south- 
westerly direction for about 850 feet to where 
the logging road bifurcates. Follow the north 
fork up the ridge for about 0.50 mile to the mine. 

This deposit was worked for asbestos during 
1955 and 1956 by the Powhatan Mining Company. 
The mine workings consist of open face cut de- 
veloped across the strike of the body at its north- 
east end and into the slope of the ridge. The cut 
has a maximum height of 30 to 35 feet and is 
about 100 feet wide at the base. 



36 



The peridotite body is a lens shaped mass that 
is elongated in a northeast-southwest direction. In 
the face of the cut it is about 75 feet wide, but it 
wedges out rapidly to the northeast. Most of the 
southwest end of the body is covered with waste 
material from the mine workings and the true 
length of the body is unknown. However, outcrops 
that appear to be in place are present for about 
200 feet southwest along strike. 

The country rock surrounding this highly al- 
tered and deeply weathered peridotite is a 
medium-grained, quartz-biotite gneiss that strikes 
N 30° E and dips 40°-50° SE. The gneiss is locally 
highly contorted and contains numerous pods and 
stringers of quartz and pegmatite. Along the 
southeast side of the peridotite the mine workings 
have exposed an excellent view of the contact 
zone. The zone is from 1 to 2 feet wide and is 
composed of schistose chlorite and vermiculite. It 
is in sharp contact with deeply weathered perido- 
tite on one side and is bordered on the other by a 
1 foot thick quartz vein and a narrow pegmatite 
dike. The pegmatite dips steeply to the southeast 
and in places cuts into the peridotite body for a 
few feet. At one place along the cut the quartz 
vein is offset 3 feet by a minor fault. 

An unusual feature of this deposit is the pres- 
ence of an amphibolite dike that intrudes the 
peridotite. The dike is 8 feet wide and crops out 
about the center of the cut and near the base. It 
is a black massive, equigranular, medium-grained 
rock composed of hornblende and plagioclase. 
Hornblende composes about 96 percent of the rock 
and occurs as anhedral crystals that average 2 to 
3 mm. in diameter. Plagioclase composes the re- 
maining 4 percent and occurs as fine interstatial 
grains that average 0.5 mm. in diameter. 

Asbestos occurs as thin cross-fiber veins that 
cut the peridotite in all directions and as mass- 
fiber ore of the peripheral zone variety. Evidently 
some mass-fiber ore was recovered from this de- 
posit, but no estimate of the tonnage is available. 

A small body of enstatolite is present about 
300 feet north of SR 1100 and 0.35 mile east of 
the entrance to the logging road that leads to 
Coldsides Mountain mine. Some prospecting was 
done here by the Powhatan Mining Company, but 
no asbestos ore was mined. 

Harris prospect : This deposit is located in east- 
ern Jackson County 1.5 miles, airline, northwest 
of Owens Gay and 1.3 miles, airline, southwest of 
Tennessee Gap. It can be reached by travelling on 



State Highway 281 for about 11 miles northwest 
of its intersection with U.S. Highway 64 to SR 
1762 at Wolf Mountain. Turn east onto SR 1762 
and travel about 0.8 mile to where a northeast 
flowing tributary joins Tennessee Creek. The de- 
posit is on the southeast side of this tributary 
stream about 1200 feet southwest of SR 1762. 

The deposit consists of a small pear-shaped out- 
crop of highly altered dunite or peridotite. It is 
alined northeast-southwest with the small end to- 
ward the northeast. The largest dimension does 
not exceed 50 feet. A narrow contact zone of fine- 
to coarse-grained, schistose vermiculite completely 
encloses the deposit. The peridotite adjacent to 
the vermiculite zone is very talcose. In the vermi- 
culite zone on the east side of the body an un- 
usually large crystal of tourmaline was found. 
The crystal was completely fracture and it could 
not be removed intact, but it was at least 24 inches 
long and 6 inches in diameter. Its long axis was 
alined perpendicular to the walls of the vermicu- 
lite zone. The country rock adjacent to the perido- 
tite varied from a fine-grained, equigranular bio- 
tite granite (Whiteside granite) to a coarse- 
grained muscovite-biotite augen gneiss. 

The Powhatan Mining Company prospected this 
deposit sometime between 1952 and 1954. The 
peripheral zone was exposed completely around 
the deposit and from material present in the 
dump some asbestos was present. However, it was 
evidently of insufficient quantity to justify further 
development. 

GLENVILLE-NORTON AREA 

The Glenville-Norton area is in the southern 
part of Jackson County and lies northwest of and 
parallel to the Lake Toxaway area. A number of 
small, lenticular masses of ultramafic rocks are 
known to occur within a distance of 2 miles north- 
east and 4 miles southwest of Glenville. Asbestos 
has been mined from 5 of these deposits by the 
Powhatan Mining Company. Most of the work 
was done between 1950 and 1955. 

Bryson-Manus mines: These two mines are lo- 
cated near the crest of a prominent ridge, 1.0 mile, 
airline, northwest of Norton. The deposits can be 
reached by travelling on SR 1149 for 1.8 miles 
northwest of Norton. Turn south onto a farm road 
that leads to the C. H. Bryson farm. 

The Bryson mine is located about 700 feet south 
of the farmhouse in a small gap at the northwest 
end of the ridge. The mining operation has largely 



37 



Figure 6 




SCALE 



0.5 



2 Mi 
-J 



les 



Cashiers 75Quad 



MAP SHOWING LOCATION OF ASBESTOS MINES 
IN CHATTOOGA RIDGE ARE A, JACKSON CQ f NC 



38 



Figure 6. Map showing location of asbestos mines in Chat- 
tooga Ridge area, Jackson County, North Carolina. 



Figure 7 




Scale 



Q5 



2 Miles 



GLENVILLE,NC 
75' QUAD. 



BIG RIDGE ,N.C 
75' QUAD 



MAP SHOWING LOCATION OF ASBESTOS MINES IN THE 
GLENVILLE- NORTON AREA 



Figure 7. Map showing location of asbestos mines in the 
Glenville-Norton area. 



39 



destroyed or covered the original form of this 
body and only a few outcrops remain in place. It 
was evidently a lense shaped body 150 to 200 feet 
long and about 50 feet wide with the long dimen- 
sion alined northeast. Waste material present in 
the mine dump indicates that the composition of 
the body ranged from relative unaltered dunite to 
highly talcose peridotite, and that the entire body 
was laced with numerous thin veins of cross-fiber 
asbestos. A cut in the face of the ridge adjacent 
to the east side of the deposit exposes a sequence 
of coarse-grained, quartz-biotite gneiss inter- 
layered with fine-grained biotite granite (White- 
side granite). The gneiss strikes N 50° E and dips 
20° SE. The contact between the peridotite and 
country rock is not exposed. 

Considerable asbestos is reported to have been 
mined from this deposit. Evidently most of it oc- 
curred in the peripheral zone along the east and 
southeast side of the deposit. Mass-fiber ore was 
the most important variety, but some cross-fiber 
asbestos was also recovered. 

The Manus mine is located about 1000 feet 
southwest of the Bryson mine on the south slope 
of the same ridge. This deposit is quite similar to 
the one at the Bryson mine, but it appears to be 
a separate body. It is about 55 feet wide and is ex- 
posed for 100 feet along strike. The northern end 
continues into the face of the mine cut and its 
true length could not be determined. 

The contact zone, which completely encloses 
the exposed portion of the peridotite body, is well 
exposed in the face of the cut. It varies from less 
than 1 foot to over 3 feet in width and is com- 
posed of a thin layer of dark-brown vermiculite, 
a zone of mass-fiber asbestos mixed with varying 
amounts of talc and a thin zone of schistose talc. 
The vermiculite zone is in sharp contact with 
quartz-biotite gneiss and the talc zone is in sharp 
contact with the peridotite. A quartz vein 20 feet 
long is present in the contact zone on the east 
side of the body near the top of the cut. 

An unknown amount of cross-and mass-fiber 
asbestos was mined from this deposit. 

Henderson mine: The site of this abandoned 
mine is located about 100 feet north of SR 1145 
at a point 0.3 mile east of the intersection of SR 
1145 and SR 1149. 

The mine workings were located on the south 
slope of the ridge, but they have been backfilled 
and leveled over. The area is now a plowed field 
and there are no outcrops in place. A small 



amount of mass-and cross-fiber ore is reported to 
have been mined from this deposit. 

Alders mine: This deposit is located near the 
crest of Peak Knob, 1.3 miles northeast of Glen- 
ville. It can be reached by travelling on SR 1129 
for 1.9 miles northeast of its intersection with 
State Highway 107. Turn southeast onto SR 1126 
and travel 0.15 mile to a farm road on the west 
side of SR 1126. The deposit is located 600 feet 
west of an abandoned farmhouse at the end of this 
farm road. 

This deposit was worked about 1955 and the 
openings have been backfilled and levelled over. 
There are no outcrops in the vicinity of the work- 
ings and the character of the ultramafic body and 
the relationship of the asbestos to it could not be 
determined. However, several large outcrops of tal- 
cose peridotite are present about 300 feet east of 
the mine workings. According to a local resident 
the mine workings consisted of two open cut 
trenches, one was located on the north side of the 
ridge and the other on the south side. Each cut 
was about 100 feet long and 25 feet wide. A 
rather large amount of asbestos ore, probably of 
the mass-fiber variety, was mined from this de- 
posit. 

Holden mine: This deposit is located about 1300 
feet southwest of the Alders mine on the south- 
west side of Peak Knob. It lies on the west side of 
a small stream 200 feet west of the Holden house. 

The deposit is composed mostly of relatively 
unaltered dunite and crops out discontinuously 
for about 200 feet along strike (northeast) . Some 
prospecting was done around the edges of the 
body and a small amount of cross-and slip-fiber 
asbestos was recovered. 

OTHER MINES AND PROSPECTS 

Macon County 

Higdon mine: A large body of dunite is located 
about 1000 feet east of SR 1001 (Ellijay Creek 
Road), 4.0 miles northeast of the intersection of 
SR 1001 and U.S. Highway 64. This intersection 
is located 4.5 miles southeast of Franklin. 

The deposit is roughly circular in outline and 
is about 1000 feet in diameter. It is composed 
mostly of green, medium-grained, unaltered oli- 
vine and is well exposed on the west slope of a 
prominent ridge. 

Along the east and southeast end of the deposit, 
adjacent to the contact zone, a number of cross- 



40 



Figure 8 




le^. 



0.5 



Scale 



2 Miles 



MAP SHOWING LOCATION OF PERIDOTITES IN 



Drbin 75Quad 



EL LI J AY CREEK AREA, MACON CO. 



Figure 8. Map showing location of peridorires in Ellijay Creek 
area, Macon County. 



41 



fiber veins are present. The veins range from t 
inch up to 8 inches in width and are composed of 
light tan to buff-colored fibrous asbestos. Some 
prospecting work has been done by Major Higdon 
and a small amount of ore has been mined. The 
quality of the asbestos is excellent, but the amount 
that can be mined economically is limited. 

Peterman mine : This deposit is located in south- 
ern Macon County, 1 mile north of the Georgia 
state line and 0.4 mile east of U.S. Highway 23- 
441. It is on the property of R. T. Peterman and 
lies on the southwest slope of a prominent hill, 
850 feet east of Little Tennessee River and 200 
feet east of the Tallulah Falls Railroad. 

The deposit is composed of dunite or peridotite 
that has been largely altered to soapstone. It is a 
narrow lense shaped mass that strikes northeast- 
southwest and is about 600 feet long and varies 
from 150 feet wide at the southwest end to 30 
feet wide at the northeast end. It is in contact 
with a highly contorted, fine-grained, quartz- 
biotite gneiss that contains interlayers of medium- 
grained muscovite-garnet schist and pegmatite. 
The gneiss strikes N 30° E and dips 40°-60° NW. 

The deposit was worked by the Powhatan Min- 
ing Company prior to 1950. A series of open cut 
trenches are present around the south and east 
side of the body and a large tonnage of mass-fiber 
asbestos of the peripheral zone variety is reported 
to have been recovered. 

Commissioner Creek prospect: This deposit is 
located 1.2 miles, airline, southwest of the Peter- 
man mine on the south side of Craig Mountain. 
It can be reached by travelling on SR 1101 for 0.8 
mile west of its intersection with SR 1102 (old 
U.S. Highway 23-441), 0.4 mile north of the 
Georgia state line. The deposit is located 1500 
feet northwest of the last house that can be driven 
to on SR 1101. 

The deposit is about 500 feet long and 150 feet 
wide with the long dimension alined northeast. 
It forms many large, massive outcrops and the 
northeast end of the body stands up as much as 
30 feet above the surrounding surface. The com- 
position varies considerably, but it appears to be 
mostly a highly altered peridotite that is very 
fibrous in places. A specimen collected from the 
center of the deposit had the following mineral 
composition : anthophyllite, 27 percent ; tremolite, 
33 percent; olivine, 27 percent, chlorite, 8 per- 
cent; talc, 3 percent; serpentine and magnesite, 
trace; others (magnetite and limonite), 2 percent. 



A small amount of peripheral zone mass-fiber 
ore was mined from the south end of the deposit 
by the Powhatan Mining Company prior to 1942. 
Some prospecting was also done at the northeast 
end but evidently no ore was present. 

Caldwell County 

Johns River mine: This deposit is located in 
western Caldwell County, 3.2 miles, airline, south- 
west of Collettsville on the east side of Johns 
River. It can be reached by travelling on SR 1328 
for 1.6 miles southeast of its intersection with SR 
1335, 1.0 mile northeast of the Burke-Caldwell 
county line. The mine is located near the crest of 
a steep hill 300 feet south of SR 1328 and 500 
feet east of the river. 

The body occurs as a northeast-southwest 
trending dike that can be traced for about 1 mile 
along strike by a series of narrow, discontinuous 
outcrops. The width of the body could not be 
determined because of the lack of outcrops and 
soil cover, but it appears to average less than 
50 feet. 

The most conspicuous feature of this deposit 
is the complete replacement of olivine by serpen- 
tine. The original rock was obviously a dunite 
composed of irregular shaped olivine grains that 
ranged from 1 to 4 mm. in diameter. Serpentine 
has replaced olivine and fine granules of mag- 
netite now mark boundaries and fractures in 
the original olivine grains. Weathering bleaches 
the serpentine and the texture and composition of 
the rock is accentuated by the contrast in the 
white to gray serpentine and the black magnetite 
that marks the grain boundaries. 

Thin section studies reveal that in addition to 
serpentine and magnetite, chlorite is also present. 
It occurs as flakes and aggregates with the mag- 
netite and often forms a corona around the mag- 
netite. The mineral composition of a typical 
specimen of this rock is as follows : serpentine, 70 
percent; magnetite, 18 percent; chlorite, 11 per- 
cent; magnesite, 1 percent. 

Asbestos occurs in the most southwesterly out- 
crop as cross-fiber veins. The veins range from a 
few inches up to 1.5 feet wide and cut across the 
strike of the deposit at moderate to steep angles. 
In addition to anthophyllite, talc is often present 
in the veins and there is considerable serpentine 
along the contact between the vein and wall rock. 
The anthophyllite fiber is relatively long, white 
and has a silky appearance. 



42 



Figure 9 




1 Mile 



Collettsville 

7.5 Minute Quad. 



MAP SHOWING LOCATION OE JOHNS RIVER 
ASBESTOS PROSPECT, CALDWELL CO,N.C 



N 

I 



Figure 9. Map showing location of Johns River asbestos 
prospect Caldwell County, North Carolina. 



43 



The deposit has been worked by means of two this deposit, but the limited tonnage present pre- 

cuts that drift into the body from the northwest eludes any extensive development. The deposit 

side. The cuts are narrow and only about 10 to 15 was last worked about 1953 by Mr. F. B. Simpson 

feet long. A small amount of exceptionally high- of Raleigh, North Carolina, 
grade anthophyllite asbestos has been mined from 



44 



Evaluation and Benef iciation 



by 

Thomas J. Wright 

Introduction 

Nine ore samples were submitted to the North Carolina State College Minerals Research Laboratory 
for evaluation. Each sample was subjected to a flowsheet simulating the conventional dry processing of 
asbestos. The Laboratory also investigated a wet process for more effective treatment of the finer size 
ranges. The samples were typical with regard to the variety of minerals found in the deposits but did 
not represent the average mineral grades of the deposits. 



DRY PROCESSING 

The samples were treated by stage grinding, 
screening, and aspirating as shown in Figure 10. 
This type of process favors recovery of long fibers, 
which are important in some end uses. However, 
for purposes of comparison this process served 
well. Screening and aspiration below 60 mesh was 
not attempted because the efficiency of screening 
and aspiration decreased with decreasing particle 
size. Although the flowsheet should be modified 
to suit each type of ore, for comparative reasons 
all samples were treated the same. In some cases 
the oversize should have been recirculated, while 
in others the oversize contained so much chlorite 
and enstatite that recirculation would have been 
of doubtful value. Recovery of anthophyllite 
coarser than 60 mesh could be improved by re- 
circulation of oversize; however, fiber grade 
might decrease. Treatment of the minus 60 mesh 
fines would also improve recovery but the grade 
would probably be more difficult to maintain. In 
every case the weight of the dust fraction was 
very low. 

The results of dry processing are listed in Tables 
1, 2 and 3, and the mineral percentages were ob- 
tained by particle count. 

Sample 1855 A: The selected sample from the 
Burleson mine was relatively low grade, short 
fibered anthophyllite ore. Only a small percentage 
of fiber was recovered above 28 mesh, and the 
grade of the fiber decreased with decreasing fiber 
length. The plus 28 mesh oversize contained about 
the same amount of anthophyllite as the plus 60 
mesh fiber product; however, there were several 
important differences between the two fractions: 
(1) the oversize had considerably more enstatite 
and chlorite, while the principal contaminant in 
the fiber was talc, and (2) the anthophyllite in the 
oversize was locked. Approximately 20 percent by 



weight of fibrous product was recovered above 
60 mesh and this represented 42 percent of the 
anthophyllite. 

Sample 1855B: The composite sample from 
the Burleson mine was higher in grade and had 
slightly longer fibers than the preceding sample. 
The chlorite content in the fiber product was some- 
what high in comparison with other samples. The 
oversize fractions were high in both chlorite and 
enstatite, and with the exception of the 28 mesh 
product, were relatively low in anthophyllite. The 
fines were quite low in comparison to the head 
sample. Forty-six percent of the anthophyllite was 
recovered in fiber products containing 56 percent 
anthophyllite and 31 percent talc. 

Sample 1856: The sample from the Blue Rock 
mine was noticeably free of enstatite and quite 
high in anthophyllite, although the fiber length 
was short. Very little anthophyllite longer than 
28 mesh was present in the fiber product ; however, 
the plus 60 mesh fiber represented 46 percent of 
the ore weight. The oversize was quite high in 
chlorite and the fines had nearly the same mineral 
composition as the fiber products. 

Sample 1857A: This sample from the New- 
dale mine was quite high in anthophyllite, with 
the principal contaminants being chlorite and talc. 
Chlorite was present in the 48 and 60 mesh fiber 
products; however, the bulk of the chlorite was 
in the oversize fractions. This sample was con- 
sidered relatively long fibered with 64 percent of 
the ore weight being recovered above 60 mesh as 
a fiber product and 74 percent of the anthophyllite 
reporting in these fractions. The fiber product was 
quite weathered and was stained with iron oxide. 

Sample 1857B: Although this sample was also 
from the Newdale mine, it differed from the pre- 



45 



Asbestos Ore 



Jaw Crusher 



Hammer Mill 



1 

Rotating Screen 
Aspiration Hood 



+20 mesh -fiber 



— Cyclone — 

1 

Filter Bog 



+20 mesh 



Hommer Mill 



Rotating Screen 
Aspiration Hood 



+20 mesh fiber--* — Cyclone — 
Filter Bag 



+20 mesh 

l 

Hammer Mill 



Rotating Screen 



As 



jiration Hood, 



+28 mesh fiber-^ — Cyclone — 
Filter Bag 



+28 mesh 



+48 mesh fibers — Cyclone — 
Filter Bog 



20 mesh 



-20 mesh 



—28 mesh 

i 

Rotating Screen 
Aspiration Hood 



+48 mesh 



-48 mesh 



-t-60 mesh fiber-^ Cvclone - 

Filter Baa 



Rotating Screen 
Aspiration Hood 



+60 mesh 



-60 mesh 



46 



Figure 10. Flowsheet for treatment of asbestos ore. 



BURLESON MINE— 1855A — SELECTED SAMPLE 





Wt. 




Fiber 




Oversize 


Fines 


Filter 




% of Total 




Mineral Nam* 


Ave. 


+20 


+ 28 


+48 


+ 60 +28 +48 +60 


—60 


Dust 


Fiber 


O'size 


Fines 


Dust 


Anthophyllite 


16 


64 


45 


33 


21 24 10 5 


1 1 


63 


42 


40 


16 


2 


Enstatite 


44 


3 


15 


15 


21 45 60 58 


40 


1 


7 


71 


22 


T 


Talc 


35 


31 


37 


49 


55 25 22 30 


45 


34 


28 


41 


30 


1 


Olivine 
























Chlorite 


4 


T 


T 


1 


13 6 6 


1 


1 


5 


88 


7 


T 


Serpentine 


T 


T 


T 


T 


T T 


T 












Magnesite 


1 


1 


T 


T 


1 T T T 


2 












Others 


1 


1 


3 


2 


13 2 1 


1 


1 










% Weight 


100 


1.5 


2.7 


11.6 


4.3 13.9 21.9 19.9 


23.7 


0.5 


20.1 


55.7 


23.7 


0.5 








BURLESON MINE — 1855B — COMPOSITE SAMPLE 












Anthophyllite 


44 


55 


64 


47 


47 65 37 17 


27 


61 


46 


40 


12 


I 


Enstatite 


24 


10 


8 


9 


8 21 32 53 


33 


1 


13 


59 


29 


T 


Talc 


25 


26 


23 


42 


43 T 21 20 


37 


37 


45 


23 


30 


2 


Olivine 


T 


T 


T 




T 


T 












Chlorite 


6 


7 


4 


1 


1 13 9 9 


2 




18 


75 


7 




Serpentine 


T 


1 


T 


















Magnesite 


T 








T 


T 












Others 


1 


1 


1 


1 


1111 


1 


1 










% Weight 


100 


3.2 


16.8 


12.3 


3.9 14.1 18.5 9.4 
BLUE ROCK MINE — 1856 


20.6 


1.2 


36.2 


42.0 


20.6 


1.2 


Anthophyllite 


65 


79 


87 


65 


70 52 61 60 


63 


77 


49 


22 


29 


T 


Enstatite 
























Talc 


27 


19 


12 


34 


27 16 16 22 


34 


22 


48 


16 


36 


T 


Olivine 


T 


T 






1 














Chlorite 


6 


1 




1 


2 21 20 15 


2 




9 


81 


10 


T 


Serpentine 


T 


T 




T 


T T 














Magnesite 


T 


T 




T 


T 














Others 


2 


1 


T 


T 


1 10 3 3 


1 


1 


8 


76 


16 


T 


% Weight 


100 


2.6 


5.2 


25.8 


12.4 9.0 8.3 7.7 


29.0 


0.01 


46.0 


25.0 


29.0 


0.01 



Table 1. Distribution and composition of products from dry process. 



NEWDALE MINE 1857A— WEATHERED 





Wt. 




Fiber 








Oversize 


Fines 


Filter 




% of Total 




Mineral Name 


Ave. 


+20 


+28 


+48 


+60 


+ 28 


+48 


+60 


—60 


Dust 


Fiber 


O'size 


Fines 


Dust 


Anthophyllite 


70 


84 


86 


74 


64 


63 


43 


31 


55 




74 


19 


7 




Enstatite 


1 








1 




1 


1 


2 












Talc 


21 


15 


13 


22 


28 


24 


36 


40 


30 




49 


37 


14 




Olivine 


1 






T 






1 


1 














Chlorite 


6 




T 


3 


6 


11 


18 


26 


12 




10 


71 


19 




Serpentine 


T 




T 




T 






T 


T 












Magnesite 


T 






T 




1 






T 












Others 


1 


1 


1 


1 


1 


1 


1 


1 


1 












% Weight 


100 


35.2 


14 


10.5 


4.3 


14 


7 


5.3 


9.6 


0.01 


64.0 


26.4 


9.6 


0.01 










NEWDALE MINE — 1857B — 


HARD ORE 












Anthophyllite 


54 


70 


75 


54 


46 


64 


52 


30 


38 


61 


36 


49 


15 


T 


Enstatite 


14 


3 


5 


3 


6 


15 


20 


29 


22 


6 


9 


43 


48 


T 


talc 


23 


23 


18 


40 


46 


7 


13 


28 


38 


30 


42 


23 


35 


T 


Olivine 


1 


1 


T 






3 




1 






4 


96 






Chlorite 


6 


2 


1 


2 


1 


9 


13 


10 


1 


2 


9 


87 


4 


T 


Serpentine 


T 


T 


























Magnesite 


T 




T 


T 




T 






T 












Others 


2 


1 


1 


1 


1 


2 


2 


2 


1 


1 


22 


64 


14 


T 


% Weight 


100 


4.4 


10.7 


14.6 


1.8 


30 


10.5 


7.2 


20.7 


0.02 


31.5 


47.7 


20.7 


0.02 










RATTLESNAKE MINE— 


-1858- 


-HARD 


ORE 












Anthophyllite 


29 


33 


50 


42 


25 


54 


24 


17 


14 


69 


40 


50 


7 


3 


Enstatite 


36 


24 


18 


16 


28 


28 


43 


48 


46 


1 


15 


67 


18 


T 


Talc 


27 


40 


30 


40 


45 


5 


20 


28 


27 


29 


39 


45 


15 


1 


Olivine 


5 


T 


T 


T 


T 


3 


9 


4 


10 




T 


69 


31 




Chlorite 


2 


2 


1 


1 


1 


9 


3 


1 


2 


T 


13 


74 


13 


T 


Serpentine 


T 


T 


T 






T 


















Magnesite 


T 


T 


T 


T 








1 


T 












Others 


1 


1 


1 


1 


1 


1 


1 


1 


1 


1 










% Weight 


100 


0.4 


5.2 


18.4 


3.8 


8.3 


22 


26 


14.5 


1.3 


27.8 


56.3 


14.5 


1.3 



Table 2. Distribution and composition of products from dry processes. 



47 



MILLER MINE— 1859— HARD ORE 



Mineral Name 

Anthophyllite 

Enstatite 

Talc 

Olivine 

Chlorite 

Serpentine 

Magnesite 

Others 

% Weight 



Anthophyllite 

Enstatite 

Talc 

Olivine 

Chlorite 

Serpentine 

Magnesite 

Others 

% Weight 



Anthophyllite 

Enstatite 

Talc 

Olivine 

Chlorite 

Serpentine 

Magnesite 

Others 

% Weight 



Wt. 

Ave. 


+ 20 


Fiber 

+ 28 


+48 


+ 60 


+ 28 


Oversize 

+48 


+ 60 


Fines 
—60 


Filter 
Dust 


Fiber 


% of Total 
O'size Fines 


Dm 


59 

5 

29 

1 
4 


62 

6 

29 

T 
T 


78 
3 


70 
1 


57 
3 


64 
11 


62 
2 


41 
4 


39 
10 


64 
1 


47 
20 


41 
48 


11 
32 


1 

T 


18 

T 
T 


28 

T 


36 
1 

1 


6 

14 


28 
6 


46 
1 
5 


45 
4 
1 


35 


37 
8 
2 


36 
14 
94 


25 
78 

4 


2 


T 


T 


























T 

2 

100 


1 

2 
4.9 


T 


1 


1 


5 


2 


2 


1 


T 


23 


69 


8 


T 


10.3 


17.7 


7.3 


15.6 


14.7 


11.8 


16.3 


1.4 


40.2 


42.1 


16.3 


1.4 








ASBESTOS MINE — 1872A — CROSS FIBER 












97 


96 


97 


99 


96 


97 


97 


94 


95 


94 


59 


30 


8 


3 


3 


4 


3 


1 


4 


2 


3 


6 


5 


6 


62 


23 


10 


5 


T 
















T 


T 










T 

T 

100 


T 
53.1 


T 
4.0 


T 

T 

1.4 


T 
1.4 


T 
14.1 


T 
12.0 


T 
3.2 


T 

T 

7.6 


T 
3.2 


59.9 


29.3 


7.6 


3.2 








ASBESTOS MINE 1872B— MASS FIBER 












86 


87 


90 


91 


78 


92 


82 


68 


67 


94 


54 


37 


6 


3 


14 


13 


10 


9 


21 


6 


18 


31 


31 


6 


48 


35 


16 


1 


T 






T 


1 




T 


T 


1 












T 


T 




T 






T 


1 


T 












T 
100 


T 
34.5 


T 
12.9 


T 
3.6 


T 
2.1 


T 
22.4 


T 
12.1 


T 
2.4 


T 
7.3 


T 

2.7 


53.1 


36.9 


7.3 


2.7 



Table 3. Distribution and composition of products from dry process. 



1855A 1855B 

Color* 

Amber filter 61.8 66.6 
Blue filter 61.0 65.0 
Green filter 61.8 63.0 
Bulk Density (ft. 3 ) 10.84 8.05 
Ignition Loss 4.71 4.08 
% Moisture 0.04 0.03 
P H 8.0 8.3 
% Fe 2 3 1-1 ]1 
Acid Sol. 7.69 5.48 
Veining Mass- Mass- 
fiber fiber 
% Anthophyllite 45 64.0 
Mineral Impurities 

Enstatite 15 8.0 

Talc 37.0 23.0 

Olivine Tr. 

Chlorite Tr. 4 

Serpentine Tr. Tr. 

Magnesite Tr. — 

Others 3.0 1.0 

* Colors determined with a reflectometer 



1856 



67.6 

57.7 

65.0 
8.23 
4.66 
0.06 
8.2 
1.2 
3.12 

Mass- 
fiber 

87.0 



12.0 



Tr. 



1857A 



75.6 

67.0 

73.6 
5.67 
4.02 
0.04 
7.2 
1.2 
4.05 

Mass- 
fiber 

86.0 



13.0 



Tr. 
Tr. 

1.0 



1857B 



68.4 
63.6 
66.7 

6.78 
4.00 
0.01 
8.1 
1.2 
1 1.28 
Mass- 
fiber 
75.0 

5.0 

18.0 

Tr. 

1.0 



Tr. 
1.0 



1858 



66.6 

63.5 

68.6 

12.57 
4.07 
0.06 
7.9 
1.2 

12.9 

Mass- 
fiber 

50 

18.0 
30.0 

Tr. 

1.0 

Tr. 

Tr. 

1.0 



1859 



73.0 

68.2 

73.6 
7.49 
4.20 
0.04 
8.6 
1.3 
6.2 

Mass- 
fiber 

78.0 

3.0 

18.0 

Tr. 

Tr. 

Tr. 
1.0 



1872A 



69.2 

75.2 

54.2 
3.30 
2.12 
0.03 
7.8 
1.5 
1.4 

Cross- 
fiber 

97 



3.0 



Tr. 



1872B 



78.4 

81.2 

65.8 
3.53 
3.40 
0.17 
7.5 
1.5 
2.0 

Mass- 
fiber 

90 



10.0 



No. 7 Shorts 
Crysotile 



64.3 
63.0 
64.5 
10.20 
14.28 
0.03 
9.3 
1.0 
54.9 



40 



50 

10.0 



Table 4. Properties of plus 28 mesh aspirated fiber. 



48 



vious sample in that it was not weathered, it was 
not stained with iron oxide, and it had much 
shorter fibers. Only 31.5 percent weight was re- 
covered as a fiber product above 60 mesh. Ensta- 
tite was present in substantial quantities. The 
anthophyllite grade decreased as the mesh size of 
the product decreased. The contrast between the 
Newdale samples illustrates how the character of 
the ore can vary within the same deposit. 

Sample 1858: The Rattlesnake mine was low 
in anthophyllite, high in enstatite, and had short 
fibers. Although the fiber product from this ore 
averaged only 42 percent anthophyllite, it con- 
tained 38 percent talc or a total of 80 percent of 
acid-resistant minerals. The preliminary treat- 
ment demonstrated that this ore will be more 
difficult to beneficiate than some of the other sam- 
ples. 

Sample 1859: The sample from the Miller 
mine was fairly high in anthophyllite, 40.2 per- 
cent fiber product weight being recovered above 
60 mesh. Little enstatite was present and chlorite 
was primarily concentrated in the oversize. 

Sample 1872A: This Asbestos mine sample 
was cross-fibered and very high grade. The treat- 
ment recovered nearly 60 percent weight as a fiber 
product coarser than 60 mesh. The effect of 
processing in this case was merely to fiberize. All 
fractions were nearly the same mineralogically. 

Sample 1872B: This Asbestos mine sample 
was essentially the same as the preceding, the 
difference being in the type of veining. This sam- 
ple was mass-fiber rather than cross-fiber. Results 
of beneficiating the two samples were similar. 

Comparison of the Plus 28 Mesh Fiber Products 

The 28 mesh fiber fractions of all samples were 
compared and the results listed in Table 4. Colors 
were measured on a reflectometer, using amber, 
blue and green filters, and the bulk densities were 
determined on a Scott Volumeter. The moisture 
content of the samples was quite low, and the loss 
on ignition showed little variation except in the 
case of the crysotile, which was a commercial 
fiber not processed by the Laboratory. The princi- 
pal contaminants were talc, enstatite and chlorite. 
Most of the granular impurities, such as enstatite, 
olivine and serpentine, are soluble in hot (90- 100° 
C) hydrochloric acid, but anthophyllite and talc 
are not. "Acid solubility" determination is there- 
fore a rapid method of estimating product grade. 



The percent anthophyllite in the fiber products 
varied considerably from sample to sample. Fac- 
tors affecting fiber grade were the grade of the 
head sample, and the liberation size of the antho- 
phyllite. In most cases the fiber grade could have 
been improved, but this was not necessary in com- 
paring ore samples. 



Product 






Acid Solubility 


+ 28 mesh 
1 st Cleaner fiber 
2nd Cleaner fiber 
3rd Cleaner fiber 
Combined undersize 






4.90 
5.29 
4.66 
4.55 
11.90 


Meaning Re-treatment 


of 


Aspirated 


Fiber 1857A 


Mesh 


% 


Weight 


Acid Solubility 


+ 65 
-65+100 
-100 + 200 
-200 + 325 

-325 




16.5 
14.3 
23.8 
20.1 
25.2 


3.91 

5.39 

14.87 

21.95 

31.65 



Screen Analysis of +28 Mesh Fiber 1858 

Table 5 

Re-treatment of sample number 1857A, as shown 
in Table 5, effectively reduced the acid-soluble 
content of the fiber product. Acid solubility of the 
screen fractions indicated re-treatment of 1858 
would produce similar results. Since finer concen- 
trates consisted principally of anthophyllite and 
talc, the similarity of these two minerals was in- 
vestigated. Table 6 compares a pure talc concen- 
trate and a pure anthophylilte concentrate, ob- 
tained by wet beneficiation and handsorting. 





Tale 


Anthophyllite 


SiOa 


56.0 


57.8 


AI2O3 


0.6 


1.6 


Fe 2 3 


3.5 


4.0 


CaO 


— 


— 


MgO 


34.2 


33.2 


Ign. Loss 


4.7 


3.4 


Acid Sol. 


2.7 


3.6 


Anthophyllite 


2 


92 


Enstatite 


Tr. 


2 


Talc 


94 


3 


Magnetite 


4 


3 


Others 


Tr. 


Tr. 


Refractive indices 


1.540-1.588 


1.596-1.624 


Color (reflectometer) 






Blue 


77.5 


80.5 


Green 


79.0 


83.0 


Amber 


78.0 


83.0 



Table 6. Comparison of chemical and mineralogical content 
of talc and anthophyllite concentrates. 

Since many of the properties of anthophyllite and 
talc are similar, mixtures of the two will probably 
be satisfactory for many uses. 



49 



Acid Leaching and Wet Processing 

Acid leaching improves the color, acid resistance 
and dielectric strength of anthophyllite and talc 
products. If the end-product is to be one in which 
the final color, dielectric strength, or acid re- 
sistance is important, and leaching is therefore 
necessary, then thought should be given to a more 
extensive wet process. A wet process has the fol- 
lowing advantages over the screen-aspiration 
process previously described: 

(1) It is more efficient in the finer sizes. 

(2) Extreme fines may be effectively removed 
by dispersion and desliming. 

(3) Cleaner separation of talc from anthophyl- 
lite can be accomplished. 

(4) Whiter products are obtained. 

However, a wet process entails high drying costs 
and may not have merit unless leaching is neces- 
sary. A flowsheet as shown in Figure 11 is par- 
ticularly adaptable to low grade, short fibered ores. 



A wet process can be employed on either the fines 
from the dry process or directly on ore. Labora- 
tory results employing a wet process on a low 
grade, short fibered ore were as follows: 







Acid 




Product 


% Weight 


Sol. %Anthophyllite 


%Talc 


Anthophyllite 


5-10 


3.4 85 


7 


Talc concentrate 


25-30 


3.9 3 


92 


Combined tailing 


45-55 


43.0 




Slime fraction 


10-15 






Head sample 


100 


33.0 





A further refinement of the process would be to 
recover the fine anthophyllite which was rejected 
in the flotation tailings. 

Conclusions 

The type of flowsheet and extent of treatment 
are, of course, determined by the final product 
specifications. In the case of an anthophyllite, a 
talc, or talc-anthophyllite product, such properties 
as color, acid resistance, dielectric strength, ther- 
mal resistance, and high surface area should be 
capitalized on in the end-use, to insure proper and 
profitable utilization of the deposits. 



Short- fiber ore or 

fines from dry processing 

\ 

Rod MiH -*- 



Screw Classifier 



overflow 



Flotation Cells 



1st Cleaner 


Cell 


1 

2nd Cleaner 


Cell 


l 

3rd Cleaner 


Cell 



middling 



•sands 



Shaking Table 



tailing 



Anthophyllite 
concentrate 



-*» tailing 



Talc 
concentrate 



Figure II. Flowsheet for low grade, short-fiber ore 



50 



DESCRIPTIONS OF PHOTOMICROGRAPHS 

Plate 1 

1. Dunite, Newdale olivine mine, thin section No. 1 00Y24, plain light, magnification 24X. 
Serpentine (S) has begun to form along the fractures and boundaries of the massive 
olivine grains (O). Acicular and thin bladed crystals of what appears to be actinolite (a) 
occur in the sheared zone at right. Aggregations of fine granules of magnetite (m) occur 
along with the serpentine. 

2. Dunite, same as number one except with crossed nicols, magnification 24X. Note the 
simultaneous extinction of several of the adjacent olivine fragments which represent larger 
original olivine grains. Undulatory extinction is also apparent in the larger olivine grains. 

3. Anthophyllite in dunite, Asbestos mine, thin section No. 50J1, plain light, magnification 
24X. Randomly oriented acicular and finely fibrous anthophyllite (A) in dunite composed 
predominantly of olivine (O). The two small areas of low relief in the upper right are 
flakes of chlorite (C) with grains of black chromite (c). Most of the smaller irregular 
opaque grains scattered over the field are magnetite (m). 

4. Anthophyllite and tremolite cutting olivine, Commissioner Creek mine, thin section No. 
57M2, plain light, magnification 24X. Acicular tremolite (t) and fibrous anthophyllite (A) 
arranged in a parallel pattern penetrate olivine (O) in a schistose portion of this deposit. 

5. Serpentine after olivine, Caldwell County, thin section No. 14C3, plain light, magnification 
24X. Typical pseudomorphs of serpentine (S) after sheared olivine. Note magnetite (m) 
granules outlining horizontally elongated original grain outlines. 

6. Amphibole peridotite, Cane River deposit, thin section No. 100Y14, plain light, magni- 
fication 24X. The moderately schistose granitic texture commonly found in the amphibole 
peridotites is illustrated by this section. Note the laths of hornblende (H), darker gray with 
cleavage, and "stretched" grains of olivine (0), light gray, are oriented roughly parallel, 
with white plagioclase (P) occurring as interstitial grains. Olivine became predominant 
with a decrease in hornblende and the complete elimination of plagioclase as a serpentized 
dunite body was approached. 



52 



BULLETIN 77 



PLATE 1 








^^# 












Photomicrographs of Typical Anthophyll ite Asbestos Ores and Related Rocks 

53 



DESCRIPTIONS OF PHOTOMICROGRAPHS 

Plate 2 

1. Alteration of enstatite to anthophyllite, mass-fiber ore, Brockton mine, thin section No. 
50J4, crossed nicols, magnification 60X. Colorless finely fibrous anthophyllite (A) which 
appears dark is forming along cleavage cracks parallel to the length of an enstatite blade 
(E) and makes the anthophyllite appear to be in short lenticular bundles when actually 
many of the fibers are much longer. In all the anthophyllite-enstatite deposits this is the 
most common manner in which anthophyllite occurs. 

2. Altered enstatite blade, mass-fiber ore, Evan's Creek mine, thin section No. 57M4, plain 
light, magnification 24X. Enstatite blade (E) containing olivine (0), talc (T), with low 
relief, anthophyllite fiber (A), and opaque magnetite (m). Note the parallel orientation 
except for the book of talc in the lower left center. 

3. Altered enstatite blade, mass-fiber ore, Mill Creek mine, thin section No. 88T4, crossed 
nicols, magnification 24X. Enstatite (E) being replaced by twinned chlorite (C) oriented 
parallel to the enstatite at center and randomly oriented at upper right. Fibrous antho- 
phyllite (A), felted talc (T), olivine remnants (0), and a curved acicular bundle of actino- 
lite (a) appear at bottom and right. 

4. Anthophyllite-olivine rock, mass-fiber ore, Old Socrates mine, thin section No. 88T9, 
plain light, magnification 24X. Anthophyllite fiber (A) has completely replaced large 
enstatite blade at bottom of field. Randomly oriented acicular anthophyllite (A) and 
magnetite (m) occur in a single large fractured grain of olivine (0) in the upper area. 
Elongated grains with high relief in the upper edge of anthophyllite blade are olivine 
remnants. 

5. Anthophyllite cutting olivine and enstatite, mass-fiber ore, Rattlesnake mine, thin section 
No. 50J6, plain light, magnification 24X. Fibrous anthophyllite (A) bundle across center 
is cutting olivine (0), upper left, and enstatite (E), upper right. Remnants with high relief 
near bottom are olivine, massive, and enstatite, displaying cleavage. Talc (T) is mineral 
in lower area and upper right that has low relief and appears almost white. Note finely 
fibrous anthophyllite associated with talc. 

6. Anthophyllite-talc schist, mass-fiber ore, Brockton mine, thin section No. 50J5, plain light, 
magnification 24X. A typical schistose texture is illustrated by this sample from the 
peripheral zone of the Brockton mine. Enstatite (E), high relief, talc (T), low relief, and 
anthophyllite (A), fibrous and acicular, are oriented roughtly parallel. Intergrowth of all 
three minerals is apparent. Magnetite (m) occurs as black granules. 



54 



BULLETIN 77 




5 *6ft 






PLATE 2 














.-&*- 








Photomicrographs of Typical Anthophyllite Asbestos Ores and Related Rocks 

55 



DESCRIPTIONS OF PHOTOMICROGRAPHS 

Plate 3 

1. Anthophyllite cones, mass-fiber ore, Blue Rock mine, thin section No. 100Y11, plain light, 
magnification 24X. Fibrous and acicular anthophyllite (A) radiates from a common center. 
White and low relief material near center is talc (T) after anthophyllite. Black irregular 
granules are magnetite (m). 

2. Anthophyllite cones, mass-fiber ore, Woody mine, thin section No. 100Y15, plain light, 
magnification 24X. This ore is quite similar to that at Blue Rock mine except the antho- 
phyllite (A) is slightly more acicular and chlorite rather than talc is the associated mineral. 
Chlorite occurs mainly with parallel orientation among the fibrous anthophyllite and is not 
apparent in plain light. Black granules are magnetite (m). 

3. Interlocking actinolite and anthophyllite, mass-fiber ore, Mill Creek mine, thin section No. 
88T3, plain light, magnification 24X. Interlocking acicular and finely fibrous actinolite 
(a) and anthophyllite (A) constitute most of the field. A remnant of wide bladed enstatite 
(E) appears at lower left. 

4. Interlocking anthophyllite and tremolite, mass-fiber ore. Carter Ridge Road deposit, thin 
section No. 61M3, plain light, magnification 24X. Interlocking short acicular, fibrous and 
prismatic anthophyllite (A) and tremolite (t) with a few olivine remnants (O) make up 
most of the field. Some fibrous anthophyllite has been partially altered to talc (T) such as 
the light area around (T) at the bottom of the field. 

5. Fine cross-fiber vein, Rattlesnake mine, thin section No. 50J8, plain light, magnification 
24X. This section is cut parallel to the length of finely fibrous anthophyllite (A) in a cross- 
fiber vein. The dark gray and black appearing areas are actually stained by red iron 
oxide. The three white streaks across the lower center are separations between antho- 
phyllite fibers which constitute the remainder of the field. 

6. Coarse cross-fiber vein, Allen mine, thin section No. 1 00Y2, plain light, magnification 
24X. A coarsely fibrous to acicular cross-fiber vein cut parallel to the length of the antho- 
phyllite fiber (A). Under abrasive action the acicular anthophyllite, which makes up the 
entire field, will separate into much finer fibers. 



56 



BULLETIN 77 



PLATE 3 








v ; ^ / rm K. A 



2 " '^""rw^i-^ 




Photomicrographs of Typical Anthophyllite Asbestos Ores and Related Rocks 

57 



DESCRIPTIONS OF PHOTOGRAPHS 

Plate 7 

1. Mass-fiber asbestos of the anthophyllite-enstatite variety from the Newdale mine, Yancey 
County, North Carolina. 

2. Typical cross-fiber vein asbestos at the Burleson mine, Avery County, North Carolina. 

3. Typical slip-fiber vein asbestos. 

4. Photograph showing contact relationships on the southwest side of the Newdale mine. 
Narrow zone of talc-chlorite-vermiculite schist (T) is in sharp contact with massive antho- 
phyllite-enstatite rock (A) and deeply weathered quartz-muscovite schist (S). 

5. Photograph showing contact relationships on the northwest side of the Blue Rock mine, 
Yancey County, North Carolina. Narrow zone of coarse-grained, emerald-green chlorite (C) 
is in sharp contact with massive anthophyllite rock (A) and reddish-brown saprolite (S). 
Chlorite zone is about 1 .5 feet wide at top of photograph. 



58 




•''■"•v^y 














1 S .l»r -,*v 



Photographs of typical ore samples, and contact relationships at the Newdale and Blue Rock Mines, 
Yancey County, North Carolina 



59 



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61